TWI774849B - Salt, acid generator comprising the same, photoresist composition and process for producing photoresist pattern - Google Patents

Abstract

The present invention relates to a salt and an acid generator comprising the same, a photoresist composition, and a process for producing a photoresist pattern. The salt comprising a group represented by the formula (aa): In formula (aa), the definition of each substituents is the same as the detail description of the specification.

Description

Salts, acid generators containing such salts, photoresist compositions, and raw materials Process for producing photoresist patterns

The disclosed invention relates to a salt and an acid generator comprising the salt, a photoresist composition, and a method of producing a photoresist pattern.

US2011/014568A1 mentions the following salts and photoresist compositions comprising said salts as acid generators.

JP2013-256496A1 mentions the following salts and photoresist compositions containing the salts as acid generators.

US2017/0247323A1 mentions the following salts and photoresist compositions comprising the salts as acid generators.

The present invention aims to provide a salt suitable for use in photoresist compositions.

The salt of the present disclosure can provide a photoresist composition that can be formed into a photoresist pattern with excellent CD uniformity.

The disclosed invention is related to the following:

<1> A salt containing a group represented by the formula (aa):

wherein X ^a and X ^b each independently represent an oxygen atom or a sulfur atom, ring W represents a C3 to C18 heterocyclic ring having a carbonate structure and capable of having a substituent, and * represents a binding position.

<2> The salt according to <1>, which includes a cation and an anion having the group represented by the formula (aa).

<3> The salt according to <2>, wherein the anion having the group represented by the formula (aa) further has a sulfonate.

<4> The salt according to any one of <1> to <3>, which has a group represented by the formula (aa1):

wherein X ^a , X ^b , the ring W and * are as defined above, ring W1 represents C3 which can have a substituent and wherein the methylene group can be replaced by -O-, -S-, -CO- or -SO ₂ - to C18 non-aromatic hydrocarbon rings.

<5> The salt according to <4>, which has an anion represented by the formula (aa2):

wherein X ^a , X ^b , the ring W and the ring W1 are as defined above, L ¹ represents C1 in which a hydrogen atom can be replaced by a fluorine atom or a hydroxyl group and in which a methylene group can be replaced by -O- or -CO- to C24 divalent saturated hydrocarbon group, and Q ¹ and Q ² each independently represent a fluorine atom or a C1 to C6 perfluoroalkyl group.

<6> The salt according to <4> or <5>, wherein the ring W1 represents an adamantane ring or a cyclohexane ring.

<7> The salt according to <5> or <6>, wherein L ¹ is represented by formula (b1-1) or formula (b1-2):

wherein L ^b2 represents a single bond or a C1 to C22 divalent saturated hydrocarbon group wherein a hydrogen atom can be replaced by a fluorine atom; L ^b3 represents a single bond or wherein a hydrogen atom can be replaced by a hydroxyl or fluorine atom and wherein a methylene group can be replaced by an oxygen atom or A carbonyl-substituted C1 to C22 divalent saturated hydrocarbon group with the limitation that the total number of carbon atoms in L ^b2 and L ^b3 is at most 22; L ^b4 represents a C1 to C22 divalent saturated hydrocarbon group in which a hydrogen atom can be replaced by a fluorine atom; and L ^b5 represents a single bond or a C1 to C22 divalent saturated hydrocarbon group in which a hydrogen atom can be replaced by a hydroxyl group or a fluorine atom and in which a methylene group can be replaced by an oxygen atom or a carbonyl group, with the limitation that all carbon atoms of L ^b4 and L ^b5 Up to 22.

<8> The salt according to any one of <1> to <7>, wherein the ring W represents a 1,3-dioxan-2-one ring.

<9> An acid generator comprising the salt according to any one of <1> to <8>.

<10> A photoresist composition comprising the acid generator according to <9> and a resin, the resin comprising a structural unit having an acid-labile group.

<11> The photoresist composition according to <10>, further comprising a salt that generates an acid whose acidity is weaker than that generated from the acid generator.

<12> A process for producing a photoresist pattern, comprising the following steps (1) to (5): (1) the step of applying the photoresist composition described in <10> or <11> on the substrate, (2) the step of forming a composition film by performing drying, (3) the exposure of the composition film to A step of irradiating, (4) a step of baking the exposed composition film, and (5) a step of developing the baked composition film to thereby form a photoresist pattern.

The salts of the present disclosure comprise groups represented by formula (aa):

wherein X ^a and X ^b each independently represent an oxygen atom or a sulfur atom, ring W represents a C3 to C18 heterocyclic ring having a carbonate structure and capable of having a substituent, and * represents a binding position.

Herein, the salts of the present disclosure are sometimes referred to as "salts (aa)".

X ^a and X ^b are preferably the same as each other, and more preferably an oxygen atom.

Preferably, X ^a and X ^b are bonded to the same carbon atom that ring W has.

Ring W represents a C3 to C18 heterocycle having a carbonate structure. for the ring W, the heterocycle may be monocyclic or polycyclic.

Examples of Ring W include a 1,3-dioxan-2-one ring, a 1,3-dioxan-2-one ring, a 1,3-dioxan-2-one ring, and A fused ring consisting of a cyclic carbonate and another ring.

Ring W may have substituents. Examples of the substituent that ring W may have include a hydroxyl group, a cyano group, a carboxyl group, a C1 to C12 alkyl group, a C1 to C12 alkoxy group, a C2 to C13 alkoxycarbonyl group, a C2 to C13 acyl group, a C2 to C13 acyloxy group, C3 to C12 alicyclic hydrocarbon groups, C6 to C12 aromatic hydrocarbon groups, and any combination thereof.

Examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl.

Examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, and hexyloxy.

Examples of the alicyclic hydrocarbon group include cyclopentyl, cyclohexyl, adamantyl, and norbornyl.

Examples of the aromatic hydrocarbon group include phenyl and naphthyl.

Examples of alkoxycarbonyl groups include methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, pentoxycarbonyl, hexyloxycarbonyl, octyloxycarbonyl, 2-ethylhexyloxycarbonyl, nonyloxycarbonyl, decyloxycarbonyl, Undecyloxycarbonyl and dodecyloxycarbonyl.

Examples of acyl groups include acetyl, propionyl, and butyryl.

Examples of alkoxyl groups include acetoxyl, propionyloxy, and butyryloxy.

Examples of combinations of these groups include any combination of C1 to C12 alkoxy and C1 to C12 alkyl, hydroxy and any combination of C1 to C12 alkyl, C1 to C12 alkyl Any combination of C12 alkoxy and C1 to C12 alkoxy, any combination of C1 to C12 alkoxy and C2 to C13 alkylcarbonyl, and any combination of C1 to C12 alkyl and C6 to C10 aromatic hydrocarbon groups.

Examples of the combination of C1 to C12 alkoxy and C1 to C12 alkyl include C2 to C24 alkoxyalkyl such as methoxymethyl, methoxyethyl, ethoxyethyl, and ethoxymethyl .

Examples of the combination of C1 to C12 alkoxy and C1 to C12 alkoxy include C2 to C24 alkoxyalkoxy, such as methoxymethoxy, methoxyethoxy, ethoxymethoxy, and Ethoxyethoxy.

Examples of combinations of C1 to C12 alkoxy groups and C2 to C13 acyl groups include C3 to C25 alkoxyalkylcarbonyl groups such as methoxyacetoxy, ethoxypropionyl, ethoxyacetyl and ethyl Oxypropionyl.

Examples of the combination of C1 to C12 alkoxy and C2 to C13 alkoxy include C3 to C25 alkoxy alkoxy, such as methoxyacetoxy, methoxypropionoxy, ethoxyacetoxy Oxy and ethoxypropionyloxy.

Examples of the combination of a C1 to C12 alkyl group and a C6 to C10 aromatic hydrocarbon group include a C7 to C22 aralkyl group, such as a benzyl group.

The substituent of ring W is preferably a hydroxyl group, a C1-C12 alkoxy group, a C2-C13 alkoxy group, a C2-C24 alkoxyalkyl group, a C2-C24 alkoxyalkoxy group or a cyano group.

Ring W is preferably a 1,3-dioxan-2-one ring or a 1,3-dioxolane-2-one ring, and more preferably a 1,3-dioxan-2-one ring .

The salt preferably has a group represented by formula (aa1):

wherein X ^a , X ^b , the ring W and * are as defined above, ring W1 represents C3 which can have a substituent and wherein the methylene group can be replaced by -O-, -S-, -CO- or -SO ₂ - to C18 non-aromatic hydrocarbon rings.

The non-aromatic hydrocarbon ring of ring W1 may be monocyclic or polycyclic. Examples of the ring include groups represented by formula (W1-1) to formula (W1-11). The ring is preferably a C3 to C12 non-aromatic hydrocarbon ring, more preferably a group represented by any one of formula (W1-1) to formula (W1-3), and still more preferably a group represented by formula ( W1-1) or a group represented by formula (W1-2).

Ring W1 preferably represents an adamantane ring or a cyclohexane ring.

Ring W1 may have a substituent. Examples of the substituent that ring W1 may have include a hydroxyl group, a cyano group, a carboxyl group, a C1 to C12 alkyl group, a C1 to C12 alkoxy group, a C2 to C13 alkoxycarbonyl group, a C2 to C13 acyl group, a C2 to C13 acyloxy group, C3 to C12 alicyclic hydrocarbon groups, C6 to C12 aromatic hydrocarbon groups, and any combination thereof. Specific examples of such substituents include the substituents of ring W as mentioned above.

The substituent of ring W1 is preferably a hydroxyl group, a cyano group or a C1 to C12 alkoxy group, more preferably a hydroxyl group, a cyano group, and still more preferably a hydroxyl group.

The salt (aa) may have a group represented by the formula (aa) in its anion or its cation.

The salt (aa) preferably includes a cation and an anion having a group represented by the formula (aa), more preferably an organic cation and an anion having a group represented by the formula (aa).

Preferably, the anion having a group represented by formula (aa) further has a sulfonate. More preferably, the anion having a group represented by formula (aa1) has a sulfonate salt.

Salt (aa) preferably includes an anion represented by formula (aa2):

wherein X ^a , X ^b , ring W and ring W1 are as defined above, L ¹ represents a C1 to C24 divalent wherein hydrogen atoms can be replaced by fluorine atoms or hydroxyl groups and wherein methylene groups can be replaced by -O- or -CO- a saturated hydrocarbon group, and Q ¹ and Q ² each independently represent a fluorine atom or a C1 to C6 perfluoroalkyl group.

For Q1 and ^Q2 , examples of perfluoroalkyl groups include trifluoromethyl, pentafluoroethyl, heptafluoropropyl, nonafluorobutyl, undecafluoropentyl, and ^{tridecafluorohexyl} .

Q ¹ and Q ² preferably each independently represent a fluorine atom or a trifluoromethyl group, and Q ¹ and Q ² are more preferably a fluorine atom.

Examples of C1 to C24 divalent saturated hydrocarbon groups for L ¹ include straight or branched chain alkanediyl groups, divalent monocyclic or polycyclic saturated hydrocarbon groups, and any combination of these groups.

Examples of alkanediyl groups include straight chain alkanediyl groups such as methylene, ethylidene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, Hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, Undecane-1,11-diyl and dodecane-1,12-diyl; and Branched alkanediyl such as ethane-1,1-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-2,2-diyl, pentane-2,4 -diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl and 2-methylbutane-1,4 - Two bases.

Examples of divalent monocyclic saturated hydrocarbon groups include cycloalkanediyl groups such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, cyclohexane Alkane-3,6-diyl and cyclooctane-1,5-diyl.

Examples of the divalent polycyclic saturated hydrocarbon group include norbornane-1,4-diyl, norbornane-2,5-diyl, 5-norbornene-2,3-diyl, adamantane-1,5 -diyl and adamantane-2,6-diyl.

For L ¹ , examples of the saturated hydrocarbon group in which the methylene group has been replaced by an oxygen atom or a carbonyl group include saturated hydrocarbon groups represented by the formula (b1-1), the formula (b1-2), and the formula (b1-3).

In the formula (b1-1), L ^b2 represents a single bond or a C1 to C22 divalent saturated hydrocarbon group in which a hydrogen atom may be replaced by a fluorine atom, and L ^b3 represents a single bond or a hydrogen atom may be replaced by a hydroxyl group or a fluorine atom and A C1 to C22 divalent saturated hydrocarbon group in which a methylene group can be replaced by an oxygen atom or a carbonyl group is limited in that the total number of carbon atoms of L ^b2 and L ^b3 is at most 22.

In formula (b1-2), L ^b4 represents a C1 to C22 divalent saturated hydrocarbon group in which a hydrogen atom may be replaced by a fluorine atom, and L ^b5 represents a single bond or a hydrogen atom may be replaced by a hydroxyl group or a fluorine atom and in which a methylene group A C1 to C22 divalent saturated hydrocarbon group in which the group may be replaced by an oxygen atom or a carbonyl group, provided that all carbon atoms of L ^b4 and L ^b5 are at most 22.

In formula (b1-3), L ^b6 represents a single bond or a C1 to C23 divalent saturated hydrocarbon group in which a hydrogen atom may be replaced by a fluorine atom, and L ^b7 represents a single bond or a hydrogen atom may be replaced by a hydroxyl group or a fluorine atom and A C1 to C22 divalent saturated hydrocarbon group in which methylene can be replaced by an oxygen atom or a carbonyl group is limited in that the total carbon number of L ^b6 and L ^b7 is at most 23, and the limited condition is that the formula (b1-3) does not include A group having a structure represented by -L ^b6 -O-CO-.

In these formulas, * represents the binding position of W1.

In formula (b1-1), formula (b1-2) and formula (b1-3), the divalent saturated hydrocarbon group includes straight chain alkanediyl, branched chain alkanediyl, monocyclic or polycyclic divalent saturated hydrocarbon group and A group in which two or more of the above-mentioned groups are combined.

L ^b2 is preferably a single bond.

L ^b3 is preferably a C1 to C4 divalent saturated hydrocarbon group.

L ^b4 is preferably a C1 to C8 divalent saturated hydrocarbon group in which a hydrogen atom can be replaced by a fluorine atom.

L ^b5 is preferably a single bond or a C1 to C8 divalent saturated hydrocarbon group.

L ^b6 is preferably a single bond or a C1 to C4 divalent saturated hydrocarbon group in which a hydrogen atom may be replaced by a fluorine atom.

L ^b7 is preferably a single bond or a C1 to C7 divalent saturated hydrocarbon group in which a hydrogen atom can be replaced by a hydroxyl group or a fluorine atom and in which a methylene group can be replaced by an oxygen atom or a carbonyl group.

Among them, the divalent saturated hydrocarbon groups of the formula (b1-1) and the formula (b1-2) are preferred.

Examples of the group represented by formula (b1-1) include those represented by formula (b1-4), formula (b1-5), formula (b1-6), formula (b1-7), and formula (b1-8) the group. The group represented by the formula (b1-1) is preferably represented by the formula (b1-4).

In the formula (b1-4), L ^b8 represents a single bond or a C1 to C22 divalent saturated hydrocarbon group in which a hydrogen atom may be replaced by a fluorine atom or a hydroxyl group.

In the formula (b1-5), L ^b9 represents a C1 to C20 divalent saturated hydrocarbon group, and L ^b10 represents a single bond or a C1 to C19 divalent saturated hydrocarbon group in which a hydrogen atom may be replaced by a hydroxyl group or a fluorine atom, with the limitation that All carbon atoms of L ^b10 and L ^b9 are at most 20.

In the formula (b1-6), L ^b11 represents a C1 to C21 divalent saturated hydrocarbon group, and L ^b12 represents a single bond or a C1 to C20 divalent saturated hydrocarbon group in which a hydrogen atom can be replaced by a hydroxyl group or a fluorine atom, with the limitation that All carbon atoms of L ^b11 and L ^b12 are at most 21.

In formula (b1-7), L ^b13 represents a C1 to C19 divalent saturated hydrocarbon group, L ^b14 represents a single bond or a C1 to C18 divalent saturated hydrocarbon group, and L ^b15 represents a single bond or wherein a hydrogen atom may be replaced by a hydroxyl group or a fluorine atom Substituted C1 to C18 divalent saturated hydrocarbon groups are limited in that all carbon atoms of L ^b13 , L ^b14 and L ^b15 are at most 19.

In formula (b1-8), L ^b16 represents a C1 to C18 divalent saturated hydrocarbon group, L ^b17 represents a C1 to C18 divalent saturated hydrocarbon group, and L ^b18 represents a single bond or C1 in which a hydrogen atom may be replaced by a hydroxyl group or a fluorine atom To C17 divalent saturated hydrocarbon groups, with the limitation that all carbon atoms of L ^b16 , L ^b17 and L ^b18 are at most 19.

In these formulas, * represents the binding position of W1.

In these formulas, the divalent saturated hydrocarbon group includes a straight chain alkanediyl group, a branched chain alkanediyl group, a monocyclic or polycyclic divalent saturated hydrocarbon group, and a group in which two or more of the foregoing groups are combined.

Specific examples of the divalent saturated hydrocarbon group include the divalent saturated hydrocarbon group mentioned for L ^b1 .

L ^b8 is preferably a single bond or a C1-C6 divalent saturated hydrocarbon group (eg, a C1-C6 alkyl group), more preferably a single bond or a C1-C4 divalent saturated hydrocarbon group (eg, a C1-C4 alkyl group).

L ^b9 is preferably a C1 to C8 divalent saturated hydrocarbon group.

L ^b10 is preferably a single bond or a C1 to C19 divalent saturated hydrocarbon group, and more preferably a single bond or a C1 to C8 divalent saturated hydrocarbon group.

L ^b11 is preferably a C1 to C8 divalent saturated hydrocarbon group.

L ^b12 is preferably a single bond or a C1 to C8 divalent saturated hydrocarbon group.

L ^b13 is preferably a C1 to C12 divalent saturated hydrocarbon group.

L ^b14 is preferably a single bond or a C1 to C6 divalent saturated hydrocarbon group.

L ^b15 is preferably a single bond or a C1 to C18 divalent saturated hydrocarbon group, and more preferably a single bond or a C1 to C8 divalent saturated hydrocarbon group.

L ^b16 is preferably a C1 to C12 divalent saturated hydrocarbon group.

L ^b17 is preferably a C1 to C6 divalent saturated hydrocarbon group.

L ^b18 is preferably a single bond or a C1 to C17 divalent saturated hydrocarbon group, and more preferably a single bond or a C1 to C4 divalent saturated hydrocarbon group.

In formula (b1-2), L ^b4 is preferably a C1-C6 divalent saturated hydrocarbon group (eg, C1-C6 alkyl group), more preferably a C1-C4 divalent saturated hydrocarbon group (eg, C1-C4 alkyl group). L ^b5 is preferably a single bond or a C1 to C4 divalent saturated hydrocarbon group (eg, a C1 to C4 alkyl group), more preferably a single bond.

Examples of the group represented by formula (b1-3) include groups represented by formula (b1-9), formula (b1-10), and formula (b1-11).

In the formula ( ^b1-9 ), L b19 represents a single bond or a C1 to C23 divalent saturated hydrocarbon group in which a hydrogen atom may be replaced by a fluorine atom, and L ^b20 represents a single bond or a hydrogen atom may be replaced by a hydroxyl group or a fluorine atom and A C1 to C23 divalent saturated hydrocarbon group in which a methylene group can be replaced by an oxygen atom or a carbonyl group is limited to all carbon atoms of L ^b19 and L ^b20 being at most 23.

In formula (b1-10), L ^b21 represents a single bond or a C1 to C21 divalent saturated hydrocarbon group in which a hydrogen atom may be replaced by a fluorine atom, L ^b22 represents a single bond or a C1 to C21 divalent saturated hydrocarbon group, and L ^b23 represents A single bond or a C1 to C21 divalent saturated hydrocarbon group in which a hydrogen atom can be replaced by a hydroxyl or fluorine atom and in which a methylene group can be replaced by an oxygen atom or a carbonyl group, with the limitation that all carbon atoms of L ^b21 , L ^b22 and L ^b23 Up to 21.

In formula (b1-11), L ^b24 represents a C1 to C21 divalent saturated hydrocarbon group in which a hydrogen atom may be replaced by a fluorine atom, L ^b25 represents a C1 to C21 divalent saturated hydrocarbon group, and L ^b26 represents a single bond or a hydrogen atom in which A C1 to C20 divalent saturated hydrocarbon group which can be replaced by a hydroxyl group or a fluorine atom and in which the methylene group can be replaced by an oxygen atom or a carbonyl group, provided that all carbon atoms of L ^b24 , L ^b25 and L ^b26 are at most 21.

In these formulas, ^* represents the binding position of W1.

In these formulas, the divalent saturated hydrocarbon group includes straight-chain alkanediyl, branched-chain alkanediyl, monocyclic or polycyclic divalent saturated hydrocarbon groups, and groups combining two or more of the foregoing groups.

Specific examples of the divalent saturated hydrocarbon group include the divalent saturated hydrocarbon group mentioned for L ¹ .

Examples of the divalent saturated hydrocarbon group in which the methylene group has been replaced by an oxygen atom or a carbonyl group include a divalent saturated hydrocarbon group having an acyloxy group. In the divalent saturated hydrocarbon group having an acyloxy group, a hydrogen atom may be replaced by a hydroxyl group, and a methylene group may be replaced by an oxygen atom or a carbonyl group.

Examples of the divalent saturated hydrocarbon group having an acyloxy group include acetyloxy, propionyloxy, butyryloxy, cyclohexylcarbonyloxy, and adamantylcarbonyloxy.

When a hydrogen atom has been replaced by a hydroxyl group or a methylene group has been replaced by an oxygen atom or a carbonyl group in the divalent saturated hydrocarbon group having an alkoxy group, examples of such groups include oxadamantylcarbonyloxy, hydroxyadamantane oxycarbonyloxy, oxocyclohexylcarbonyloxy and hydroxycyclohexylcarbonyloxy.

Examples of the group represented by formula (b1-4) include the following.

Examples of the group represented by formula (b1-5) include the following.

Examples of the group represented by formula (b1-6) include the following.

Examples of the group represented by formula (b1-7) include the following.

Examples of the group represented by formula (b1-8) include the following.

Examples of the group represented by formula (b1-2) include the following.

Examples of the group represented by the formula (b1-9) include the following.

Examples of the group represented by the formula (b1-10) include the following.

Examples of the group represented by the formula (b1-11) include the following.

L ¹ preferably represents a group represented by formula (b1-4), more preferably *1-CO-O-(CH ₂ ) _t -, wherein t represents an integer of 0 to 6 and *1 is *-C (Q ¹ )(Q ² )-binding site. t preferably represents an integer of 0, 1 or 2, more preferably an integer of 0 or 1.

Specific examples of the anion of the salt (aa) include the following.

The cation of the salt (aa) is preferably an organic cation. Examples of organic cations include organic onium cations such as organic peronium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations ion. Among them, organic sulfonium cation and organic iodonium cation are preferred, and arylsulfonium cation is more preferred.

Preferable examples of the cation include cations represented by formula (b2-1), formula (b2-2), formula (b2-3), and formula (b2-4).

In formulas (b2-1) to (b2-4), R ^b4 , R ^b5 and R ^b6 independently represent a C1 to C30 aliphatic hydrocarbon group, a C3 to C36 alicyclic hydrocarbon group, and a C6 to C36 aromatic hydrocarbon group. The aliphatic hydrocarbon group may have a substituent selected from the group consisting of a hydroxyl group, a C1 to C12 alkoxy group, a C3 to C12 alicyclic hydrocarbon group, and a C6 to C18 aromatic hydrocarbon group. The alicyclic hydrocarbon group may have a substituent selected from the group consisting of a halogen atom, a C1 to C18 aliphatic hydrocarbon group, a C2 to C4 acyl group, and a glycidyloxy group. The aromatic hydrocarbon group may have a substituent selected from the group consisting of a halogen atom, a hydroxyl group, a C1 to C18 aliphatic hydrocarbon group, and a C1 to C12 alkoxy group.

R ^b4 and R ^b5 can be bonded to form a ring together with the adjacent S ⁺ , and the methylene group in this ring can be replaced by -CO-, -O- or -S-.

R ^b7 and R ^b8 are, at each occurrence, independently hydroxy, C1 to C12 aliphatic hydrocarbon group or C1 to C12 alkoxy group, and m2 and n2 independently represent an integer from 0 to 5.

R ^b9 and R ^b10 independently represent a C1 to C36 aliphatic hydrocarbon group or a C3 to C36 alicyclic hydrocarbon group.

R ^b9 and R ^b10 may be bonded to form a ring together with adjacent S ⁺ , and the methylene group in the divalent alicyclic hydrocarbon group may be replaced by -CO-, -O- or -S-.

R ^b11 represents a hydrogen atom, a C1 to C36 aliphatic hydrocarbon group, a C3 to C36 alicyclic hydrocarbon group, or a C6 to C18 aromatic hydrocarbon group.

R ^b12 represents a C1 to C12 aliphatic hydrocarbon group in which a hydrogen atom may be replaced by a C6 to C18 aromatic hydrocarbon group, a C3 to C18 saturated cyclic hydrocarbon group, or a C1 to C12 alkoxy group or (C1 to C12 alkyl group) in which the hydrogen atom may be replaced A carbonyloxy-substituted C6 to C18 aromatic hydrocarbon group.

R ^b11 and R ^b12 may be bonded to each other to form a C1 to C10 divalent alicyclic hydrocarbon group for forming a 2-oxocycloalkyl group together with adjacent -CHCO-, and the The methyl group can be replaced by -CO-, -O- or -S-.

R ^b13 , R ^b14 , R ^b15 , R ^b16 , R ^b17 and R ^b18 independently represent a hydroxyl group, a C1 to C12 aliphatic hydrocarbon group, or a C1 to C12 alkoxy group.

L ^b31 represents -S- or -O-, and o2, p2, s2 and t2 each independently represent an integer of 0 to 5, q2 and r2 each independently represent an integer of 0 to 4, and u2 represents 0 or 1.

Preferable examples of the aliphatic hydrocarbon groups represented by R ^b4 to R ^b12 include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl , hexyl, octyl and 2-ethylhexyl. The aliphatic hydrocarbon groups represented by R ^b9 , R ^b10 , R ^b11 and R ^b12 preferably have 1 to 12 carbon atoms.

The alicyclic hydrocarbon group may be a monocyclic alicyclic hydrocarbon group or a polycyclic alicyclic hydrocarbon group. Preferred examples of monocyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, cycloheptyl and cyclooctyl. Preferable examples of the polycyclic hydrocarbon group include adamantyl, norbornyl, decalinyl and the following groups.

The alicyclic hydrocarbon group represented by R ^b9 , R ^b10 , R ^b11 and R ^b12 preferably has 3 to 18 carbon atoms, and more preferably 4 to 12 carbon atoms.

Examples of the alicyclic hydrocarbon group in which a hydrogen atom has been replaced by an aliphatic hydrocarbon group include methylcyclohexyl, dimethylcyclohexyl, and methylnorbornyl.

The alicyclic hydrocarbon group in which the hydrogen atom has been replaced by the aliphatic hydrocarbon group preferably has a total of 20 or less carbon atoms.

Examples of aromatic hydrocarbon groups include aryl groups such as phenyl, tolyl, xylyl, cumyl, mesityl, p-ethylphenyl, p-tert-butylphenyl, p-adamantylphenyl , biphenyl, naphthyl, phenanthryl, 2,6-diethylphenyl, 2-methyl-6-ethylphenyl.

When the aromatic hydrocarbon group has an alicyclic hydrocarbon group or an aliphatic hydrocarbon group, it is preferable that the alicyclic hydrocarbon group and the aliphatic hydrocarbon group have 1 to 18 carbon atoms and 3 to 18 carbon atoms, respectively.

Examples of the aromatic hydrocarbon group in which a hydrogen atom has been replaced by an alkoxy group include p-methoxyphenyl.

Examples of the aliphatic hydrocarbon group in which a hydrogen atom has been replaced by an aromatic hydrocarbon group include benzyl, phenethyl, phenylpropyl, trityl, naphthylmethyl, and naphthylethyl.

Examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy, and dodecyloxy.

Examples of acyl groups include acetyl, propionyl, and butyryl.

Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom and iodine atom.

Examples of alkylcarbonyloxy include methylcarbonyloxy, ethylcarbonyloxy, n-propylcarbonyloxy, isopropylcarbonyloxy, n-butylcarbonyloxy, 2-butylcarbonyloxy, th Tributylcarbonyloxy, pentylcarbonyloxy, hexylcarbonyloxy, octylcarbonyloxy and 2-ethylhexylcarbonyloxy.

The cyclic group formed by bonding R ^b4 and R ^b5 together with the adjacent S ⁺ may be a monocyclic or polycyclic group, a saturated or unsaturated group, an aromatic or non-aromatic group. The rings are generally 3 to 12 rings, preferably 3 to 7 rings. Examples of the ring include the following.

The cyclic group formed by bonding R ^b9 to R ^b10 together with adjacent S ⁺ may be a monocyclic or polycyclic group, a saturated or unsaturated group, an aromatic or non-aromatic group. The ring typically has C3 to C12 carbon atoms, and preferably C3 to C7 carbon atoms. Examples of the ring include thiolan-1-ium ring (tetrahydrothiophenium ring), thian-1-ium ring (thian-1- ium ring) and 1,4-oxathian-4-ium ring (1,4-oxathian-4-ium ring).

The cyclic group formed by bonding R ^b11 and R ^b12 together with -CH-CO- may be a monocyclic or polycyclic group, a saturated or unsaturated group, an aromatic or non-aromatic group. The ring typically has 3 to 12 carbon atoms, preferably 3 to 7 carbon atoms. Examples of such rings include oxocycloheptane rings, oxocyclohexane rings, oxonorbornane rings, and oxoadamantane rings.

Preferable examples of the cation of the acid generator include arylsulfonium cation, specifically, the cation of formula (b2-1).

Examples of the cation represented by the formula (b2-1) include the following.

Examples of the cation represented by the formula (b2-2) include the following.

Examples of the cation represented by formula (b2-3) include the following.

Examples of the cation represented by formula (b2-4) include the following.

Preferably, the salt (aa) is composed of anions as mentioned above and cations as mentioned above. Specific examples of the salt (aa) include the salts listed in the following table.

In the tables, each character in each row is used to represent a symbol for one of the chemical formulae specified above. For example, salt (I-1) consists of an anion of formula (I-a-1) and a cation of formula (b2-c-1) as shown below.

Among these specific examples, salt (aa) is preferably salt (I-1), salt (I-5), salt (I-10), salt (I-11), salt (I-12), Salt (I-13), Salt (I-17), Salt (I-22), Salt (I-23), Salt (I-24), Salt (I-25), Salt (I-29), Salt (I-34), salt (I-35), salt (I-36), salt (I-37), salt (I-41), salt (I-46), salt (I-47), salt ( I-48), salt (I-49), salt (I-53), salt (I-58), salt (I-59), salt (I-60), salt (I-61), salt (I -65), salt (I-70), salt (I-71), salt (I-72), salt (I-73), salt (I-77), salt (I-82), salt (I- 83) and salt (I-84).

When the salt (aa) is composed of an anion represented by the formula (aa2) and an organic cation, the salt represented by the formula (aa-a) and the compound represented by the formula (aa-b) can be prepared by mixing the salt represented by the formula (aa-b) in, for example, pyridine or the like. The salt is produced by reaction in a solvent such as chloroform or acetonitrile in the presence of a base:

wherein Q ¹ , Q ² , L ¹ , W1 , X ^a and X ^b are the same as defined above, Z ⁺ represents an organic cation, and L ¹¹ and L ¹² each independently represent a C1 to C6 alkanediyl group or a single bond.

The above reaction is usually carried out at about 5°C to 200°C, preferably at about 50°C to 150°C.

It can be prepared by mixing the salt represented by the formula (aa-c) with the compound represented by the formula (aa-d) in the presence of an acid catalyst such as p-toluenesulfonic acid in the presence of, for example, dimethylformamide, chloroform, or acetonitrile, etc. A reaction occurs in a solvent to produce a salt represented by formula (aa-a):

wherein Q ¹ , Q ² , L ¹ , W1 , X ^a , X ^b , L ¹¹ and L ¹² are the same as defined above.

Specific examples of the salt represented by formula (aa-c) include the following. These salts can be prepared according to the methods described in JP2007-224008A1, JP2011-116747A1 or JP2012-224611A1.

Specific examples of the compound represented by formula (aa-d) include the following. Compounds represented by formula (aa-d) are commercially available.

<acid generator>

The acid generator of the present disclosure includes a salt (aa). The acid generator may contain two or more salts (aa). The acid generator may contain one or more known acid generators in addition to the salt (aa).

In the photoresist composition, the acid is generated by an acid generator with light used for lithography. Acid catalysis acts on the acid labile groups in the resin to cleave the acid labile groups.

Acid generators known in the art may be non-ionic acid generators or Ionic acid generator. Examples of nonionic acid generators include organo-halogen compounds; sulfonate compounds, eg, 2-nitrobenzyl sulfonate, aromatic sulfonate, oxime sulfonate, N-sulfonyloxy imide, sulfonimidyloxyketone, and diazonaphthoquinone 4-sulfonate; and bisulfite compounds, such as dibismuth, ketone ketone, and sulfonamidodiazomethane. Examples of the ionic acid generator include onium salt compounds such as diazonium salts, phosphonium salts, peronium salts, and iodonium salts. Examples of anions of onium salts include sulfonic acid anions, sulfonamidoimide anions, and sulfonamidomethide anions.

Specific examples of acid generators known in the art are included in JP 63-26653 A, JP 55-164824 A, JP62-69263 A, JP63-146038A, JP63-163452A, JP62-153853A, JP63-146029A, US Pat. Acid generators described in No. 3,779,778, US Patent No. 3,849,137, German Patent No. 3914407, and European Patent No. 126,712. Other examples of the acid generator include acid generators described in JP2013-68914A, JP2013-3155A, and JP2013-11905A.

The acid generator known in the art is preferably a fluorine-containing acid generator, and more preferably a fluorine-containing organic sulfonate acid generator.

Preferred examples of acid generators known in the art include salts represented by formula (B1):

wherein Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C1 to C6 perfluoroalkyl group, and L ^b1 represents a compound in which a methylene group may be replaced by -O- or -CO- and a hydrogen atom may be replaced by a fluorine atom or a hydroxyl group C1 to C24 divalent saturated hydrocarbon group, and Y represents a methyl group which may have a substituent or a C3 to C18 monovalent alicyclic ring which may have a substituent and wherein the methylene group may be replaced by -O-, -CO- or -SO ₂ - family of hydrocarbon groups, and Z1 ⁺ represents an organic cation.

Hereinafter, the salt represented by formula (B1) may be referred to as "salt (B1)".

For Q ^b1 and Q ^b2 , examples of perfluoroalkyl groups include examples of perfluoroalkyl groups of Q ¹ and Q ² and are preferably trifluoromethyl. Preferably, Q ^b1 and Q ^b2 each independently represent a fluorine atom or a trifluoromethyl group, and Q ^b1 and Q ^b2 are more preferably a fluorine atom.

For L ^b1 , examples of C1 to C24 divalent saturated hydrocarbon groups include alkanediyl groups, divalent monocyclic or polycyclic saturated hydrocarbon groups, and any combination of these groups.

Specific examples of the divalent saturated hydrocarbon group include these groups as the saturated hydrocarbon group represented by L ¹ .

For L ^b1 , examples of the saturated hydrocarbon group in which the methylene group has been replaced by an oxygen atom or a carbonyl group include saturated hydrocarbon groups represented by formula (b1-1), formula (b1-2), and formula (b1-3) as mentioned above Hydrocarbyl.

In these formulas of L ^b1 , * represents the binding position of Y.

Among them, the saturated hydrocarbon groups of the formula (b1-1) and the formula (b1-3) are preferred.

Examples of the group represented by formula (b1-1) include those represented by formula (b1-1) as mentioned above Groups represented by (b1-4), formula (b1-5), formula (b1-6), formula (b1-7), and formula (b1-8).

In these formulas of L ^b1 , * represents the binding position of Y.

Examples of the group represented by formula (b1-3) include groups represented by formula (b1-9), formula (b1-10), and formula (b1-11).

In these formulas of L ^b1 , * represents the binding position of Y.

For L ^b1 , specific examples of the groups represented by the formula (b1-4) to the formula (b1-11) include the groups mentioned above, except that * represents the binding position of Y.

The monovalent alicyclic hydrocarbon group of Y may be monocyclic or polycyclic (eg, a spirocyclic ring).

Preferable examples of the alicyclic hydrocarbon group represented by Y include the alicyclic hydrocarbon groups represented by formula (Y1) to formula (Y11) and formula (Y36) to formula (Y38). Preferable examples of the alicyclic hydrocarbon group represented by Y and in which the methylene group has been replaced by -O-, -SO ₂ - or -CO- include those from formula (Y12) to formula (Y35) and formula (Y39) to formula The alicyclic hydrocarbon group represented by (Y41).

Among the groups represented by these formulas, groups represented by formula (Y1) to formula (Y20), formula (Y30), formula (Y31), formula (Y39) and formula (Y41) are preferred; more Preferably a group represented by formula (Y11), formula (Y15), formula (Y16), formula (Y20), formula (Y30), formula (Y31), formula (Y39) and formula (Y40); and more Preferred are groups represented by formula (Y11), formula (Y15), formula (Y30), formula (Y39) and formula (Y40).

When Y has a spirocyclic ring (eg, groups represented by formula (Y28) to formula (Y35), formula (Y39) and formula (Y40)), the spirocyclic ring is preferably between two oxygen atoms The alkanediyl group has a fluorine atom. Furthermore, the methylene group attached to the oxygen atom in the alkanediyl group forming the acetal structure is not replaced by the fluorine atom.

Substituents on the methyl group of Y include halogen atoms, hydroxyl groups, C3 to C16 alicyclic hydrocarbon groups, C6 to C18 aromatic hydrocarbon groups, glycidyloxy groups, and -(CH ₂ ) _j2 -O-CO-R ^b1' - , wherein R ^b1' is a C1 to C16 alkyl group and j2 is an integer from 0 to 4.

Substituents on the alicyclic hydrocarbon group of Y include halogen atoms, hydroxyl groups, C1 to C12 alkyl groups, C1 to C12 hydroxyl-containing alkyl groups, C1 to C12 alkoxy groups, C3 to C16 alicyclic hydrocarbon groups, C6 to C18 aromatic groups family of hydrocarbon groups, C7 to C21 aralkyl groups, C2 to C4 aryl groups, glycidyloxy groups, and -(CH ₂ ) _j2 -O-CO-R ^b1' -, wherein R ^b1' is C1 to C16 alkyl and j2 is an integer from 0 to 4.

The substituent on the alicyclic hydrocarbon group of Y does not have a carbonate structure.

Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom and iodine atom.

Examples of cycloaliphatic hydrocarbon groups include cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl, norbornyl, and adamantyl.

Examples of aromatic hydrocarbon groups include aryl groups such as phenyl, naphthyl, anthracenyl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumene group, mesityl, biphenyl, phenanthryl, 2,6-diethylphenyl and 2-methyl-6-ethylphenyl.

Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, 2-ethylhexyl, and dodecyl.

Examples of hydroxy-containing alkyl groups include hydroxymethyl and hydroxyethyl.

Examples of C1 to C12 alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy, and dodecyloxy .

Examples of aralkyl groups include benzyl, phenylpropyl, phenethyl, naphthylmethyl or naphthylethyl.

Examples of acyl groups include acetyl, propionyl, and butyryl.

Examples of Y include the following groups.

Y preferably represents a C3 to C18 alicyclic hydrocarbon group which may have a substituent and wherein the methylene group has been replaced by -O-, -SO ₂ - or -CO-, more preferably may have a substituent and wherein the methylene group Adamantyl that has been replaced by -O-, _-SO2- or -CO-, and still more preferably adamantyl, hydroxyadamantyl, oxadamantyl or the following groups.

where * denotes the binding position.

Preferable examples of the sulfonic acid anion of the salt represented by formula (B1) include formula (B1-A-1) to formula (B1-A-55), and preferably formula (B1-A-1) to formula (B1-A-4), formula (B1-A-9), formula (B1-A-10), formula (B1-A-24) to formula (B1-A-33), formula (B1-A- 36) The salts represented by formula (B1-A-40) and formula (B1-A-47) to formula (B1-A-55).

In these formulas, the symbols Q ^b1 and Q ^b2 are as defined above, and R ⁱ² , R ⁱ³ , R ⁱ⁴ , R ⁱ⁵ , R ⁱ⁶ and R ⁱ⁷ each independently represent C1 to C4 alkyl, preferably methyl or ethyl R ⁱ⁸ represents a C1 to C12 aliphatic hydrocarbon group [preferably a C1 to C4 alkyl group], a C5 to C12 monovalent alicyclic hydrocarbon group, or a combination thereof, preferably a methyl group, an ethyl group, a cyclohexyl group or a diamond alkyl, and L ^A4 represents a single bond or a C1 to C4 alkanediyl group.

Examples of the sulfonic acid anion of the salt represented by the formula (B1) are included in The sulfonic acid anion described in JP2010-204646A1.

Specific examples of the anion of the salt represented by the formula (B1) include the following anions.

Among them, the preferred formula is from formula (B1a-1) to formula (B1a-3), formula (B1a-7) to formula (B1a-16), formula (B1a-18), formula (B1a-19) and formula ( B1a-22) to The sulfonic acid anion represented by the formula (B1a-34).

Examples of organic ions represented by Z1 ⁺ include onium cations (such as perium cations, iodonium cations, ammonium cations, benzothiazolium cations, and phosphonium cations), especially from formula (b2-1) to formula ( The cation represented by b2-4).

The salt represented by the formula (B1) is preferably the formula (B1a-1) to the formula (B1a-3), the formula (B1a-7) to the formula (B1a-16), the formula (B1a-18), the formula (B1a) -19) and a salt composed of an anion represented by any one of formulae (B1a-22) to (B1a-34) and a cation represented by formula (b2-1) or formula (b2-3).

Specific examples of the salt represented by the formula (B1) include the following salts represented by the formula (B1-1) to the formula (B1-48). Among them, salts containing aryl perionium cations are preferred, and formulas (B1-1) to (B1-3), (B1-5) to (B1-7), and (B1-11) are more preferred ) to formula (B1-14), formula (B1-20) to formula (B1-26), formula (B1-29), formula (B1-31) to formula (B1-48).

When the acid generator contains another salt other than the salt (aa), the weight ratio of the salt (aa) to the other salt is usually 1:99 to 99:1, preferably 2:98 to 98:2, more preferably It is 5:95 to 95:5, more preferably 10:90 to 90:10 and still more preferably 15:85 to 85:15.

The photoresist composition of the present disclosure includes an acid generator containing a salt (aa) and a resin having an acid-labile group, and the resin is referred to as "resin (A)".

The photoresist composition may further contain other than the salt (aa) as an acid generator. Another salt, quencher or solvent.

The content of the acid generator is preferably 1 part by mass to 40 parts by mass, and more preferably 3 parts by mass to 35 parts by mass with respect to 100 parts of the resin (A).

The resin (A) usually has a structural unit containing an acid-labile group. Hereinafter, the structural unit may be referred to as "structural unit (a1)".

Preferably, the resin (A) has another structural unit other than the structural unit (a1), that is, a structural unit without an acid-labile group, and the structural unit is sometimes referred to as "structural unit (s)" .

Herein, "acid-labile group" means a group having a hydrophilic group such as a hydroxyl or carboxyl group by removing a leaving group by the action of an acid.

<Structural Unit (a1)>

The structural unit (a1) is derived from a compound having an acid-labile group, and the compound may be referred to as "monomer (a1)".

The resin (A) is preferably an acid-labile group represented by the formula (1) and the formula (2).

In formula (1), R ^a1 , R ^a2 and R ^a3 each independently represent a C1 to C8 alkyl group, a C3 to C20 alicyclic hydrocarbon group, or a group consisting of a C1 to C8 alkyl group and a C3 to C20 alicyclic hydrocarbon group group, and R ^a1 and R ^a2 may be bonded to each other to form a C3 to C20 alicyclic hydrocarbon group together with the carbon atoms bonded to R ^a1 and R ^a2 , "na" and "ma" respectively represent an integer of 0 or 1, which The constraints are that at least one of them represents 1, and ^* represents the binding position.

In the formula (2), R ^a1' and R ^a2' each independently represent a hydrogen atom or a C1 to C12 hydrocarbon group, and R ^a3' represents a C1 to C20 hydrocarbon group, and R ^a2' and R ^a3' may be bonded to each other to X and the carbon atoms bonded to R ^s2' and R ^a3' together form a C3 to C20 heterocyclic group, and one or more -CH ₂ - in the hydrocarbon group and the heterocyclic group may be replaced by -O- or -S- , X represents an oxygen atom or a sulfur atom, "na'" represents an integer 0 or 1, and ^* represents a binding position.

For R ^a1 , R ^a2 and R ^a3 , specific examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, heptyl, and octyl.

Cycloaliphatic hydrocarbon groups may be monocyclic or polycyclic. Examples of alicyclic hydrocarbon groups include monocyclic alicyclic hydrocarbon groups, such as C3 to C20 cycloalkyl groups (eg, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl); and polycyclic alicyclic hydrocarbon groups, such as deca Hydronaphthyl, adamantyl, norbornyl and the following:

where ^* denotes the binding position.

The alicyclic hydrocarbon group preferably has 3 to 16 carbon atoms.

Examples of groups consisting of an alkyl group and an alicyclic hydrocarbon group include methylcyclohexane group, dimethylcyclohexyl, methylnorbornyl, adamantylmethyl and norbornylethyl.

"ma" is preferably 0. "na" is preferably 1.

When the divalent hydrocarbon group is formed by bonding R ^a1 and R ^a2 to each other, examples of the moiety -C(R ^a1 )(R ^a2 )(R ^a3 ) include the following groups, and the divalent hydrocarbon group preferably has 3 to 12 carbon atoms:

wherein R ^a3 is the same as defined above, and ^* denotes the binding position.

For formula (2), examples of the hydrocarbon group include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group consisting of two or more thereof.

Examples of the aliphatic hydrocarbon group and the alicyclic hydrocarbon group include those described above. Examples of aromatic hydrocarbon groups include aryl groups such as phenyl, naphthyl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumyl, homo- Trimethylphenyl, biphenyl, anthracenyl, phenanthryl, 2,6-diethylphenyl and 2-methyl-6-ethylphenyl.

Examples of the heterocyclic group formed by bonding R ^a2' to R ^a3' and then to X and the carbon atom to which R ^a2' and R ^a3' are bonded include the following:

where ^* denotes the binding position.

In formula (2), at least one of R ^a1' and R ^a2' is preferably a hydrogen atom. "na'" is preferably 0.

Examples of the group represented by the formula (1) include the following: a group represented by the formula (1), wherein R ^a1 , R ^a2 and R ^a3 each independently represent a C1 to C18 alkyl group, ma is 0, and na is 1, such as tert-butyl; a group represented by formula (1) in which R ^a1 and R ^a2 are bonded to each other to form an adamantyl ring, R ^a3 is a C1 to C18 alkyl group, ma is 0, and na is 1, such as 2-alkyl-2-adamantyl; a group represented by formula (1), wherein R ^a1 and R ^a2 are C1 to C18 alkyl groups, R ^a3 is adamantyl, ma is 0, and na is 1, eg 1-(1-adamantyl)-1-alkylalkoxycarbonyl.

Specific examples of the group represented by formula (1) include the following.

Specific examples of the group represented by formula (2) include the following.

The monomer (a1) is preferably a monomer having an acid-labile group and an ethylenically unsaturated group in its side chain, more preferably an acid-labile group in its side chain (meth)acrylate monomer of , and still more preferably a (meth)acrylate monomer having a group represented by formula (1) or formula (2).

The (meth)acrylate monomer having an acid-labile group in its side chain is preferably a monomer containing a C5 to C20 alicyclic hydrocarbon group. Resins comprising structural units derived from such monomers can increase the resolution of photoresist patterns to be prepared from the resins.

The structural unit derived from the (meth)acrylate monomer having the group represented by the formula (1) is preferably represented by the formula (a1-0), the formula (a1-1) and the formula (a1-2) one of the structural units.

In each formula, L ^a01 , L ^a1 and L ^a2 independently represent -O- or *-O-(CH ₂ ) _k1 -CO-O-, wherein k1 represents an integer from 1 to 7 and * represents -CO- The binding positions of R ^a01 , R ^a4 and R ^a5 independently represent a hydrogen atom or a methyl group, and R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 independently represent C1 to C8 alkyl, C3 to C18 lipid A cyclic hydrocarbon group or a group formed by combining a C1 to C8 alkyl group with a C3 to C18 alicyclic hydrocarbon group, m1 represents an integer of 0 to 14, n1 represents an integer of 0 to 10, and n1' represents 0 to 3 the integer.

Hereinafter, the structural units represented by the formula (a1-0), the formula (a1-1), and the formula (a1-2) are referred to as "structural unit (a1-0)", "structural unit (a1-1)" and "Structural unit (a1-2)".

Resin (A) may contain two or more of such structural units.

L ^a01 is preferably *-O- or *-O-(CH ₂ ) _f1 -CO-O-, wherein * represents the binding position of -CO- and f1 represents an integer of 1 to 4; and more preferably *-O - or *-O-CH ₂ -CO-O-; and *-O- is particularly preferred.

R ^a01 is preferably methyl.

For R ^a02 , R ^a03 and R ^a04 , examples of the alkyl group, the alicyclic hydrocarbon group and the group formed by combining the alkyl group with the alicyclic hydrocarbon group include those mentioned for R ^a1 , R ^a2 and R ^a3 By.

The alkyl group preferably has 1 to 6 carbon atoms.

The alicyclic hydrocarbon group preferably has 3 to 8 carbon atoms, and more preferably 3 to 6 carbon atoms. The alicyclic hydrocarbon group is preferably a saturated aliphatic cyclic hydrocarbon group. A group formed by combining an alkyl group with an alicyclic hydrocarbon group preferably has a total of 18 carbon atoms or less, and examples of the group include methylcyclohexyl, dimethyl ring Hexyl and methyl norbornyl.

Each of R ^a02 and R ^a03 is preferably C1 to C6 alkyl, and more preferably methyl and ethyl.

R ^a04 is preferably a C1-C6 alkyl group and a C5-C12 alicyclic hydrocarbon group, and more preferably a methyl group, an ethyl group, a cyclohexyl group and an adamantyl group.

Each of L ^a1 and L ^a2 is preferably *-O- or *-O-(CH ₂ ) _f1 -CO-O-, wherein * represents the binding position of -CO- and f1 is the same as defined above and more preferably *-O- or *-O-CH ₂ -CO-O-; and particularly preferably *-O-.

Each of R ^a4 and R ^a5 is preferably methyl.

For R ^a6 and R ^a7 , examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, heptyl, 2-ethylheptyl, and octyl.

For R ^a6 and R ^a7 , examples of alicyclic hydrocarbon groups include monocyclic alicyclic hydrocarbon groups such as cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, cycloheptyl, and methylcycloheptyl; and polycyclic alicyclic groups Cyclic hydrocarbon groups such as decalinyl, adamantyl, norbornyl and methylnorbornyl.

For R ^a6 and R ^a7 , examples of groups consisting of an alkyl group and an alicyclic hydrocarbon group include aralkyl groups such as benzyl and phenethyl.

The alkyl group represented by R ^a6 and R ^a7 is preferably a C1 to C6 alkyl group, more preferably a methyl group, an ethyl group or an isopropyl group, and still more preferably an ethyl group or an isopropyl group.

The alicyclic hydrocarbon group represented by R ^a6 and R ^a7 is preferably a C3 to C8 alicyclic hydrocarbon group, more preferably a C3 to C6 alicyclic hydrocarbon group.

"m1" is preferably an integer of 0 to 3 and more preferably 0 or 1.

"n1" is preferably an integer of 0 to 3 and more preferably 0 or 1.

"n1'" is preferably 0 or 1.

Examples of the structural unit (a1-0) include structural units represented by formula (a1-0-1) to formula (a1-0-12), preferably by formula (a1-0-1) to formula (a1- 0-10) represented the structural unit.

Examples of the structural unit (a1-0) further include those in which the methyl group corresponding to R ^a01 in any one of the formulas (a1-0-1) to (a1-0-12) has been replaced by a hydrogen atom group.

Examples of the monomer from which the structural unit (a1-1) is derived include the monomers described in JP2010-204646A1 and the following monomers represented by formula (a1-1-1) to formula (a1-1-4) and Such a group in which the methyl group has been replaced by a hydrogen atom in any of the formulae (a1-1-1) to (a1-1-4), and preferably by the formula (a1-1-1) to the following monomers represented by formula (a1-1-4).

Preferable examples of the structural unit (a1-2) include the structural units represented by the formula (a1-2-1) to the formula (a1-2-6) and those represented by the formula in which the methyl group corresponding to R ^a5 has been replaced by a hydrogen atom. The structural unit represented by the formula is more preferably a monomer represented by the formula (a1-2-2), the formula (a1-2-5), and the formula (a1-2-6).

When the resin contains one or more of the structural units represented by the formula (a1-0), the formula (a1-1), and the formula (a1-2), based on 100 mol% of the total structural units of the resin, The total content of the structural units is usually 10 mol% to 95 mol%, preferably 15 mol% to 90 mol% and more preferably 20 mol% to 85 mol%, still more preferably 25 mol% % to 70 mol %, and more preferably 30 mol % to 65 mol %.

Examples of the structural unit (a1) having the group represented by the formula (2) include the structural unit represented by the formula (a1-4). The structural unit is sometimes referred to as "structural unit (a1-4)".

In the formula, R ^a32 represents a hydrogen atom, a halogen atom or a C1 to C6 alkyl group which may have a halogen atom, and R ^a33 independently at each occurrence represents a halogen atom, a hydroxyl group, a C1 to C6 alkyl group, a C1 to C6 alkyl group alkoxy, C2-C4 alkoxy, C2-C4 alkoxy, acryloxy or methacryloyloxy, "la" represents an integer from 0 to 4, R ^a34 and R ^a35 each independently represent a hydrogen atom or a C1 to C12 hydrocarbon group, and R ^a36 represents a C1 to C20 hydrocarbon group, or R ^a35 and R ^a36 may be bonded together with CO bonded to it to form a divalent C3 to C20 heterocyclic group, and the hydrocarbon group or a divalent heterocyclic group The methylene group contained in the ring group may be replaced by an oxygen atom or a sulfur atom.

Examples of the alkyl group for R ^a32 and R ^a33 include methyl, ethyl, propyl, isopropyl, butyl, pentyl and hexyl. The alkyl group is preferably a C1 to C4 alkyl group, and more preferably a methyl group or an ethyl group and still more preferably a methyl group.

Examples of the halogen atom of R ^a32 and R ^a33 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

Examples of the alkyl group which may have a halogen atom include trifluoromethyl, difluoromethyl, methyl, perfluoroethyl, 2,2,2-trifluoroethyl, 1,1,2,2-tetrafluoroethyl radical, ethyl, perfluoropropyl, 2,2,3,3,3-pentafluoropropyl, propyl, perfluorobutyl, 1,1,2,2,3,3,4,4- Octafluorobutyl, butyl, perfluoropentyl, 2,2,3,3,4,4,5,5,5-nonafluoropentyl, n-pentyl, n-hexyl and n-perfluorohexyl.

Examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, and hexyloxy. The alkoxy group is preferably a C1 to C4 alkoxy group, more preferably a methoxy group or an ethoxy group, and still more preferably a methoxy group.

Examples of acyl groups include acetyl, propionyl, and butyryl. Examples of alkoxyl groups include acetoxyl, propionyloxy, and butyryloxy. Examples of the hydrocarbon group of R ^a34 and R ^a35 are the same as those described in R ^a1′ and R ^a2′ in the formula (2).

Examples of the hydrocarbon group for R ^a36 include a C1 to C20 alkyl group, a C3 to C18 alicyclic hydrocarbon group, a C6 to C18 aromatic hydrocarbon group, or a group formed by combining these groups.

Examples of alkyl groups for R ^a36 include methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, octyl, decyl, and dodecyl.

Examples of the alicyclic hydrocarbon group of R ^a36 include C3 to C18 cycloalkyl groups such as cyclopropyl, cyclohexyl and cyclooctyl.

Examples of the aromatic hydrocarbon group of R ^a36 include phenyl, naphthyl, anthracenyl, biphenyl, and phenanthryl.

In the formula (a1-4), R ^a32 is preferably a hydrogen atom.

R ^a33 is preferably C1 to C4 alkoxy, more preferably methoxy or ethoxy, and still more preferably methoxy.

"la" is preferably 0 or 1 and more preferably 0. R ^a34 is preferably a hydrogen atom. R ^a35 is preferably a C1 to C12 hydrocarbon group and more preferably a methyl group or an ethyl group.

The hydrocarbon group of R ^a36 is preferably a C1-C18 alkyl group, a C3-C18 alicyclic hydrocarbon group, a C6-C18 aromatic hydrocarbon group or a combination thereof, and more preferably a C1-C18 alkyl group, a C3-C18 alicyclic hydrocarbon group or a C7 to C18 aralkyl. The alkyl group and alicyclic hydrocarbon group of R ^a36 are preferably unsubstituted. When the aromatic hydrocarbon group of R ^a36 has a substituent, the substituent is preferably a C6 to C10 aryloxy group.

Examples of the structural unit (a1-4) include structural units derived from monomers described in JP2010-204646A1. Among them, the structural unit is preferably the following represented by the formula (a1-4-1) to the formula (a1-4-8) and more preferably the formula (a1-4-1) to the formula (a1-4) -5) represents the structural unit.

When the resin (A) has the structural unit (a1-4), the ratio is preferably 10 mol % to 95 mol % based on the total structural unit (100 mol %) of the resin (A), more preferably 15 mol % to 90 mol %, more preferably 20 mol % to 85 mol %, still more preferably 20 mol % to 70 mol %, still more preferably 20 mol % to 60 mol % Ear%.

Example package of the structural unit having an acid-labile group represented by the formula (2) A structural unit represented by formula (a1-5) is included.

In formula (a1-5), R ^a8 represents a hydrogen atom, a halogen atom or a C1 to C6 alkyl group which may have a halogen atom, Z ^a1 represents a single bond or *-(CH ₂ ) _h3 -CO-L ⁵⁴ -, wherein h3 represents an integer from 1 to 4 and * represents the binding position of L ⁵¹ , L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ each independently represent an oxygen atom or a sulfur atom, and s1 represents an integer from 1 to 3, and s1′ represents Integer from 0 to 3.

Herein, the structural unit represented by formula (a1-5) is sometimes referred to as "structural unit (a1-5)".

Examples of the halogen atom include a fluorine atom and a chlorine atom, and a fluorine atom is preferable.

Examples of the alkyl group which may have a halogen atom include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, 2-ethyl Hexyl, octyl, fluoromethyl and trifluoromethyl.

In the formula (a1-5), R ^a8 preferably represents a hydrogen atom, a methyl group or a trifluoromethyl group.

L ⁵¹ preferably represents an oxygen atom.

Preferably, one of L ⁵² and L ⁵³ represents an oxygen atom, and the other represents a sulfur atom.

s1 preferably represents 1. s1' represents an integer from 0 to 2. Z ^a1 preferably represents a single bond or *-CH ₂ -CO-O-, wherein * represents the binding position of L ⁵¹ .

Examples of the structural unit (a1-5) include structural units derived from monomers mentioned in JP2010-61117A1, which preferably include the following.

Among them, the structural unit represented by the formula (a1-5-1) and the formula (a1-5-2) is more preferable.

When the resin (A) has the structural unit (a1-5), the content thereof is usually 1 mol % to 50 mol %, preferably 3 mol % to 100 mol % of the total structural unit of the resin. 45 mol % and more preferably 5 mol % to 40 mol % and still more preferably 5 mol % to 30 mol %.

Another example of the structural unit (a1) further includes the following.

When the resin (A) has any of these structural units, the content thereof is usually 10 mol % to 95 mol %, preferably 15 mol % based on 100 mol % of the total structural units of the resin % to 90 mol %, more preferably 20 mol % to 85 mol %, still more preferably 20 mol % to 70 mol %, still more preferably 20 mol % to 70 mol % 60 mol%.

The structural unit (s) is derived from a monomer having no acid-labile group.

The structural unit (s) preferably has a hydroxyl group or a lactone ring.

Hereinafter, the structural unit (s) having a hydroxyl group is referred to as "structural unit (a2)", and the structural unit (s) having a lactone ring is referred to as "structural unit (a3)".

The hydroxyl group of the structural unit (a2) may be an alcoholic hydroxyl group or a phenolic hydroxy group.

When a KrF excimer laser (wavelength: 248 nm) lithography system or high-energy laser (eg, electron beam and extreme ultraviolet) is used as the exposure system, a resin containing a structural unit (a2) having a phenolic hydroxyl group is preferable . When an ArF excimer laser (wavelength: 193 nm) is used as the exposure system, it is preferable to use a resin containing the structural unit (a2) having an alcoholic hydroxyl group, and it is more preferable to contain the structural unit (a2-1) explained later. of resin.

The resin (A) may have two or more of the structural units (a2).

Examples of the structural unit (a2) having a phenolic hydroxyl group include the structural unit represented by the formula (a2-A):

In formula (a2-A), R ^a50 represents a hydrogen atom, a halogen atom, a C1 to C6 alkyl group or a C1 to C6 haloalkyl group, A ^a50 represents a single bond or ^* -X ^a51 -(A ^a52 -X ^a52 ) _nb - , wherein ^* represents the binding position of the carbon atom bonded to R ^{a50, A a52 represents} a C1 to C6 alkanediyl group, X ^a51 and X ^a52 represent -O-, -CO-O- or -O-CO-, and nb Represents an integer of 0 or 1; R ^a51 at each occurrence is independently a halogen atom, C1 to C6 alkyl, C1 to C6 alkoxy, C2 to C4 alkoxy, C2 to C4 hydroxy, acryl or methyl and mb represents an integer of 0 to 4.

In the formula (a2-A), examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and examples of the C1 to C6 alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl and hexyl, and preferably C1 to C4 alkyl, more preferably C1 to C2 alkyl, and particularly preferably methyl.

Examples of C1 to C6 haloalkyl include trifluoromethyl, pentafluoroethyl, heptafluoropropyl, heptafluoroisopropyl, nonafluorobutyl, nonafluoro-2-butyl, nonafluoro-tert-butyl, Perfluoropentyl and perfluorohexyl.

Examples of C1 to C6 alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, second butoxy, third butoxy, pentoxy and hexyloxy, and preferably C1 to C4 alkoxy, and more preferably C1 to C2 alkoxy, and particularly preferably methoxy.

Examples of the C2-C4 yloxy group include acetyloxy, propionyloxy, and butyryloxy, and examples of the C2-C4 aryloxy group include acetyloxy, propionyloxy, and butyryloxy.

R ^a51 is preferably methyl.

R ^a50 is preferably a hydrogen atom and a C1 to C4 alkyl group, more preferably a hydrogen atom, a methyl group and an ethyl group, and still more preferably a hydrogen atom and a methyl group.

With respect to A ^a50 , examples of ^* -X ^a51 -(A ^a52 -X ^a52 ) _nb - include ^* -O-, ^* -CO-O-, ^* -O-CO-, ^* -CO-OA ^a52 -CO-O -, ^* -O-CO-A ^a52 -O-, ^* -OA ^a52 -CO-O-, ^* -CO-OA ^a52 -O-CO-, ^* -O-CO-A ^a52 -O-CO-, Preferred are ^* -CO-O-, ^* -CO-OA ^a52 -CO-O- and ^* -OA ^a52 -CO-O-.

Regarding A ^a52 , examples of alkanediyl include ethylidene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, pentane-1,5-diyl base, hexane-1,6-diyl, butane-1,3-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane -1,4-diyl and 2-methylbutane-1,4-diyl.

A ^a50 is preferably a single bond, ^* -CO-O- or ^* -CO-OA ^a52 -O-CO-, more preferably a single bond, ^* -CO-O- or ^* -CO-O-CH ₂ -O -CO-, and even more preferably a single bond or ^* -CO-O-.

In formula (a2-A), mb is preferably 0, 1 or 2, more preferably 0 or 1 and particularly preferably 0.

In formula (a2-A), the hydroxyl group on the phenyl group is preferably located in the ortho or para position and more preferably in the para position.

Examples of the structural unit (a2) include structural units derived from monomers described in JP2010-204634A1 and JP2012-12577A1. Preferable examples of the structural unit (a2) include structural units represented by formulae (a2-2-1) to (a2-2-4) and those represented by formulae in which the methyl group corresponding to R ^a50 has been replaced by a hydrogen atom structural unit.

Among them, more preferred are the structural units represented by the formula (a2-2-1) and the formula (a2-2-4), and the structural unit represented by the formula in which the methyl group corresponding to R ^a50 has been replaced by a hydrogen atom.

When the resin (A) has a structural unit represented by the formula (a2-A), the content thereof is usually 5 mol % to 80 mol % and preferably 10 mol % to 10 mol % based on the total of the structural units of the resin. 70 mol %, more preferably 15 mol % to 65 mol %, and still more preferably 20 mol % to 65 mol %.

Examples of the structural unit (a2) having an alcoholic hydroxyl group include the structural unit represented by the formula (a2-1):

wherein R ^a14 represents a hydrogen atom or a methyl group; R ^a15 and R ^a16 independently represent a hydrogen atom, a methyl group or a hydroxyl group; L ^a3 represents *-O- or *-O-(CH ₂ ) _k2 -CO-O-, wherein * represents the binding position of -CO-, and k2 represents an integer from 1 to 7; and o1 represents an integer from 0 to 10.

Hereinafter, the structural unit represented by the formula (a2-1) will be referred to as "structural unit" (a2-1)”.

In formula (a2-1), R ^a14 is preferably a methyl group. R ^a15 is preferably a hydrogen atom. R ^a16 is preferably a hydrogen atom or a hydroxyl group. L ^a3 is preferably *-O- or *-O-(CH ₂ ) _f2 -CO-O-, wherein * represents the binding position of -CO- and f2 represents an integer of 1 to 4; more preferably *-O- and *-O- _CH2 -CO-O-; and still more preferably *-O-, and o1 is preferably 0, 1, 2 or 3 and more preferably 0 or 1.

Examples of the monomer from which the structural unit (a2-1) is derived include compounds mentioned in JP2010-204646A.

Preferable examples of the structural unit (a2-1) include the structural units represented by the formula (a2-1-1) to the formula (a2-1-6).

Among them, structural units represented by formula (a2-1-1), formula (a2-1-2), formula (a2-1-3) and formula (a2-1-4) are more preferred, and even more preferred are Structural units represented by formula (a2-1-1) and formula (a2-1-3).

When the resin (A) has the structural unit (a2-1), its content is usually 1 mol % to 45 mol %, preferably 1 mol % to 40 mol %, based on the total of the structural units of the resin. , and more preferably 1 mol % to 35 mol %, still more preferably 2 mol % to 20 mol %, and still more preferably 2 mol % to 10 mol %.

Examples of the lactone ring of the structural unit (a3) include monocyclic lactone rings such as β-propiolactone ring, γ-butyrolactone ring and γ-valerolactone ring; and condensed rings consisting of a monocyclic lactone ring formed with another ring. Among them, the γ-butyrolactone ring and the fused lactone ring formed by the γ-butyrolactone ring and the other ring are preferred.

Preferable examples of the structural unit (a3) include structural units represented by the formula (a3-1), the formula (a3-2), the formula (a3-3), and the formula (a3-4).

In the formula, L ^a4 , L ^a5 and L ^a6 each independently represent *-O- or *-O-(CH ₂ ) _k3 -CO-O-, wherein * represents the binding position of the carbonyl group, and k3 represents 1 to 7 R ^a18 , R ^a19 and R ^a20 each independently represent a hydrogen atom or a methyl group, R ^a21 represents a C1 to C4 monovalent aliphatic hydrocarbon group, R ^a24 represents a hydrogen atom, a halogen atom or a C1 to C6 alkane which may have a halogen atom group, R ^a22 , R ^a23 and R ^a25 each independently represent a carboxyl group, a cyano group or a C1 to C4 aliphatic hydrocarbon group, L ^a7 represents an oxygen atom, * ¹ -OL ^a8 -O-, * ¹ -OL ^a8 -CO-O -, * ¹ -OL ^a8 -CO-OL ^a9 -CO-O- or * ¹ -O ¹ -L ^a8 -O-CO-L ^a9 -O-, wherein L ^a8 and L ^a9 each independently represent C1 to C6 Divalent alkanediyl group, * ¹ represents the bonding position of the carbonyl group, p1 represents an integer of 0 to 5, q1 and r1 each independently represent an integer of 0 to 3, and w1 represents an integer of 0 to 8.

Examples of the aliphatic hydrocarbon group represented by R ^a21 , R ^a22 , R ^a23 and R ^a25 include alkyl groups such as methyl, ethyl, propyl or butyl.

Examples of the alkyl group represented by R ^a24 include methyl, ethyl, propyl, butyl, pentyl and hexyl, preferably C1 to C4 alkyl, and more preferably methyl and ethyl.

Examples of the halogen atom represented by R ^a24 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

As for R ^a24 , examples of the alkyl group having a halogen atom include trifluoromethyl, pentafluoroethyl, heptafluoropropyl, heptafluoroisopropyl, nonafluorobutyl, nonafluoro-2-butyl, nonafluoro- tert-butyl, perfluoropentyl, perfluorohexyl, trichloromethyl, tribromomethyl and triiodomethyl.

Regarding L ^a8 and L ^a9 , examples of alkanediyl include methylene, ethylidene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl and Hexane-1,6-diyl, butane-1,3-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1 ,4-diyl and 2-methylbutane-1,4-diyl.

Preferably, L ^a4 , L ^a5 and L ^a6 independently represent *-O- or *-O-(CH ₂ ) _d1 -CO-O-, wherein * represents the binding position of -CO-, and d1 represents 1 an integer up to 4. More preferably, L ^a4 , L ^a5 and L ^a6 are *-O- and *-O-CH ₂ -CO-O-, and even more preferably L ^a4 , L ^a5 and L ^a6 are *-O-.

R ^a18 , R ^a19 and R ^a20 are preferably methyl groups. R ^a21 is preferably methyl. Preferably, R ^a22 and R ^a23 are independently at each occurrence carboxy, cyano or methyl.

Preferably, p1, q1 and r1 each independently represent an integer from 0 to 2, and more preferably, p1, q1 and r1 each independently represent 0 or 1.

R ^a24 is preferably a hydrogen atom or a C1 to C4 alkyl group, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group.

L ^a7 preferably represents an oxygen atom or * ¹ -OL ^a8 -CO-O-, more preferably an oxygen atom, * ¹ -O-CH ₂ -CO-O- or * ¹ -OC ₂ H ₄ -CO-O -.

Formula (a3-4)' is preferably the following.

In the formula, R ^a24 and L ^a7 are respectively as defined above.

Examples of monomers from which the structural unit (a3) is derived include the monomers mentioned in US2010/203446A1, US2002/098441A1 and US2013/143157A1.

Examples of the structural unit (a3) include the following.

Other examples of the structural unit (a3) include those of the formula (a3) in which the methyl groups corresponding to R ^a18 , R ^a19 , R ^a20 and R ^a24 of the formulae (a3-1) to (a3-4) have been replaced by hydrogen atoms. -1) to the structural unit represented by the formula (a3-4).

When the resin (A) has the structural unit (a3), its content is preferably 5 mol % to 70 mol %, more preferably 10 mol % to 65 mol %, based on the total of the structural units of the resin, And more preferably, it is 10 mol % to 60 mol %.

When the resin (A) has a structural unit (a3-1), a structural unit (a3-2), a structural unit (a3-3) or a structural unit (a3-4), based on the total of the structural units of the resin, its content It is preferably 5 mol% to 60 mol%, more preferably 5 mol% to 50 mol%, and more preferably 10 mol% to 50 mol%.

Other examples of the structural unit (s) include a structural unit having a fluorine atom and a structural unit having a hydrocarbon that is not removed therefrom by the action of an acid.

Hereinafter, the structural unit (s) having a halogen atom is referred to as "structural unit (a4)".

The halogen atom of the structural unit (a4) may be a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. The structural unit (a4) preferably has a fluorine atom.

Examples of the structural unit (a4) include the following.

In the formula, R ⁴¹ represents a hydrogen atom or a methyl group, and R ⁴² represents a C1 to C24 saturated hydrocarbon group having a fluorine atom, in which a methylene group may be substituted with an oxygen atom or a carbonyl group.

Examples of saturated hydrocarbon groups include C1 to C24 chain hydrocarbon groups, alicyclic hydrocarbon groups including monocyclic hydrocarbon groups or polycyclic hydrocarbon groups, and any combination of these groups.

Examples of chain hydrocarbon groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl.

Examples of cycloaliphatic hydrocarbon groups include cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl, decalinyl, adamantyl, norbornyl and the following groups:

Examples of combinations of these groups include any combination of an alkyl group or an alkanediyl group with a cycloaliphatic hydrocarbon group, which specifically includes -[alkanediyl]-[cycloaliphatic hydrocarbon group], -[cycloaliphatic hydrocarbon group] -[Alkyl] and -[alkanediyl]-[alicyclic hydrocarbyl]-[alkyl].

Typical examples of the structural unit (a4) include structural units represented by the formula (a4-0), the formula (a4-1), and the formula (a4-4).

In formula (a4-0), R ^5a represents a hydrogen atom or a methyl group, L ^4a represents a single bond or a C1 to C4 alkanediyl group, and L ^3a represents a C1 to C8 perfluoroalkanediyl group or a C3 to C12 perfluorocycloalkane diradical, and R ^6a represents a hydrogen atom or a fluorine atom.

For L ^4a , examples of alkanediyl groups include linear alkanediyl groups such as methylene, ethylidene, propane-1,3-diyl, and butane-1,4-diyl; and branched alkanediyl groups , such as ethane-1,1-diyl, propane-1,2-diyl, butane-1,3-diyl, 2-methylpropane-1,3-diyl and 2-methylpropane- 1,2-diradical.

Examples of perfluoroalkanediyl groups for L ^3a include difluoromethylene, perfluoroethylidene, perfluoropropane-1,3-diyl, perfluoropropane-1,2-diyl, perfluoropropane-2 ,2-diyl, perfluorobutane-1,4-diyl, perfluorobutane-2,2-diyl, perfluorobutane-1,2-diyl, perfluoropentane-1,5 -diyl, perfluoropentane-2,2-diyl, perfluoropentane-3,3-diyl, perfluorohexane-1,6-diyl, perfluorohexane-2,2-diyl base, perfluorohexane-3,3-diyl, perfluoroheptane-1,7-diyl, perfluoroheptane-2,2-diyl, perfluoroheptane-3,4-diyl, Perfluoroheptane-4,4-diyl, perfluorooctane-1,8-diyl, perfluorooctane-2,2-diyl, perfluorooctane-3,3-diyl and perfluorooctane-3,3-diyl Octane-4,4-diyl.

Examples of perfluorocycloalkanediyl of L ^3a include perfluorocyclohexanediyl, perfluorocyclopentanediyl, perfluorocycloheptanediyl, and perfluoroadamantanediyl.

L ^3a is preferably a C1 to C6 perfluoroalkanediyl group, more preferably a C1 to C3 perfluoroalkanediyl group.

L ^4a is preferably a single bond, a methylene group or an ethylidene group, more preferably a single bond or a methylene group.

Examples of the structural unit represented by the formula (a4-0) include a structural unit represented by the following formula and a structural unit represented by the following formula in which a methyl group has been replaced by a hydrogen atom.

The structural unit represented by the formula (a4-1) is as follows.

In the formula, R ^a41 represents a hydrogen atom or a methyl group; R ^a42 represents a C1 to C20 saturated hydrocarbon group which may have a substituent and in which the methylene group may be replaced by an oxygen atom or a carbonyl group, with the limitations of A ^a41 and R ^a42 each or both of which have a fluorine atom; and A ^a41 represents a C1 to C6 alkanediyl group which may have a substituent or a moiety represented by the formula (a-g1):

wherein s represents an integer from 0 to 1, A ^a42 and A ^a44 respectively represent a C1 to C5 saturated hydrocarbon group which may have a substituent, A ^a43 represents a single bond or a C1 to C5 chain hydrocarbon group or an alicyclic hydrocarbon group which may have a substituent, X ^a41 and X ^a42 represent -O-, -CO-, -CO-O- or -O-CO-, respectively, and the limitation is that the sum of the carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is respectively is 7 or less; A ^a44 is bonded to -O-CO-R ^a42 ; and both of the symbols * indicate binding positions.

The saturated hydrocarbon group of R ^a42 includes chain saturated hydrocarbon groups, alicyclic hydrocarbon groups including monocyclic hydrocarbon groups and polycyclic hydrocarbon groups, and any combination of these hydrocarbon groups.

Examples of chain saturated hydrocarbon groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, hexadecyl, pentadecyl, hexadecyl Hexyldecyl, heptadecyl and octadecyl.

Examples of alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl; and monovalent polycyclic hydrocarbon groups such as decalinyl, adamantyl, norbornyl, and the following groups , where * denotes the binding position.

Examples of combinations of these groups include alkanediyl or combinations of alkyl and cycloaliphatic hydrocarbon groups, eg -[alkanediyl]-[cycloaliphatic hydrocarbon groups], -[cycloaliphatic hydrocarbon groups]-[alkyl groups ] and -[alkanediyl]-[alicyclic hydrocarbyl]-[alkyl].

The hydrocarbon group represented by R ^a42 preferably has a substituent. Examples of the substituent include halogen atoms and groups represented by the formula (a-g3): -X ^a43 -A ^a45 (a-g3)

wherein X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group, and A ^a45 represents a C1 to C17 chain hydrocarbon group or an alicyclic hydrocarbon group which may have a fluorine atom.

Examples of the chain hydrocarbon group or alicyclic hydrocarbon group of A ^a45 include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, hexadecyl Alkyl, pentadecyl, hexyldecyl, heptadecyl, and octadecyl; monocyclic alicyclic hydrocarbon groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl; and monovalent polycyclic hydrocarbon groups , such as decahydronaphthyl, adamantyl, norbornyl and the following groups, where * denotes the binding position.

R ^a42 is preferably a chain hydrocarbon group or an alicyclic hydrocarbon group which may have a halogen atom, and more preferably an alkyl group having a halogen atom or a group represented by the formula (a-g3).

If R ^a42 is a chain hydrocarbon group or an alicyclic hydrocarbon group having a halogen atom, it is preferably a chain hydrocarbon group or an alicyclic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, and still more Preferred are C1 to C6, especially C1 to C3 perfluoroalkyl groups.

Specific examples of perfluoroalkyl include perfluoromethyl, perfluoroethyl, perfluoropropyl perfluorobutyl, perfluoropentyl, perfluorohexyl, perfluoroheptyl and perfluorooctyl. Specific examples of perfluorocycloalkyl include perfluorocyclohexyl.

Examples of the substituent for R ^a42 include a hydroxyl group, a C1 to C6 alkoxy group, and a halogen atom (eg, a fluorine atom).

If R ^a42 is a chain hydrocarbon group or an alicyclic hydrocarbon group having a group represented by the formula (a-g3), R ^a42 preferably has 15 or less carbon atoms, and more preferably 12 or less. carbon atoms.

If R ^a42 has a group represented by formula (a-g3), R ^a42 preferably has one group represented by formula (a-g3).

The chain hydrocarbon group or alicyclic hydrocarbon group having the group represented by the formula (a-g3) is preferably a group represented by the formula (a-g2): -A ^a46 -X ^a44 -A ^a47 (a-g2)

wherein A ^a46 represents a C1 to C17 chain hydrocarbon group or an alicyclic hydrocarbon group which may have a fluorine atom, X ^a44 represents a carbonyloxy group or an oxycarbonyl group, and A ^a47 represents a C1 to C17 chain hydrocarbon group or an alicyclic hydrocarbon group which may have a fluorine atom , with the proviso that A ^a46 , A ^a47 , and X ^a44 have a total of 18 or less carbon atoms, and one or both of A ^a46 and A ^a47 have a fluorine atom.

The chain hydrocarbon group or alicyclic hydrocarbon group represented by A ^a46 preferably has 1 to 6, and more preferably 1 to 3 carbon atoms.

The chain hydrocarbon group or alicyclic hydrocarbon group represented by A ^a47 preferably has 4 to 15, and more preferably 5 to 12 carbon atoms. A ^a47 is more preferably cyclohexyl or adamantyl.

Examples of the moiety represented by -A ^a46 -X ^a44 -A ^a47 include the following.

In each formula, ^* represents the binding position of the carboxyl group.

Examples of A ^a41 generally include C1 to C6 alkanediyl groups which may be straight or branched. Specific examples thereof include straight-chain alkanediyl groups such as methylene, ethylidene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl or hexane -1,6-diyl; and branched alkanediyl, such as propane-1,3-diyl, butane-1,3-diyl, 1-methylbutane-1,2-diyl or 2 -methylbutane-1,4-diyl. Examples of substituents on the alkanediyl group include hydroxy or C1 to C6 alkoxy.

A ^a41 is preferably a C1-C4 alkanediyl group, more preferably a C2-C4 alkanediyl group, and still more preferably an ethylidene group.

Examples of the alkanediyl group represented by A ^a42 , A ^a43 and A ^a44 include methylene, ethylidene, propane-1,3-diyl, butane-1,4-diyl, 2-methylpropane- 1,3-diyl or 2-methylbutane-1,4-diyl. Examples of substituents on the alkanediyl group include hydroxy or C1 to C6 alkoxy.

X ^a42 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.

Examples of the moiety represented by the formula (a-g1) wherein X ^a42 is an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group include the following:

wherein ^* and ^** denote binding positions, and ^** denotes binding positions of -O-CO-R ^a42 .

Typical examples of the structural unit represented by the formula (a4-1) include the structural unit represented by the following formula and the structural unit represented by the following formula in which the methyl group corresponding to R ^a41 has been replaced with a hydrogen atom.

Specific examples of the structural unit (a4-1) include the structural unit represented by the formula (a4-2):

wherein, R ^f5 represents a hydrogen atom or a methyl group, L ⁴⁴ represents a C1 to C6 alkanediyl group in which the methylene group can be replaced by -O- or -CO-, and R ^f6 represents a C1 to C20 saturated hydrocarbon group having a fluorine atom, The limitation is that L ⁴⁴ and R ^f6 have a total of 2 to 21 carbon atoms.

Examples of the divalent saturated hydrocarbon group of L ⁴⁴ include linear alkanediyl groups such as methylene, ethylidene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl diyl, pentane-1,5-diyl and hexane-1,6-diyl; and branched alkanediyl groups such as 1-methylpropane-1,3-diyl, 2-methylpropane- 1,3-diyl, 2-methylpropane-1,2-diyl, 1-methylbutane-1,4-diyl and 2-methylbutane-1,4-diyl.

Examples of the saturated hydrocarbon group of R ^f6 include aliphatic hydrocarbon groups and aromatic hydrocarbon groups. Aliphatic hydrocarbon groups include chain groups, cyclic groups, and combinations thereof. The aliphatic hydrocarbon group is preferably an alkyl group and a cyclic aliphatic hydrocarbon group.

Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, and 2- Ethylhexyl.

Examples of the cyclic aliphatic hydrocarbon group include any of a monocyclic group and a polycyclic group. Examples of monocyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl base. Examples of polycyclic hydrocarbon groups include decalinyl, adamantyl, 2-alkyladamantan-2-yl, 1-(adamantan-1-yl)alkane-1-yl, norbornyl, methylnorbornyl base and isobornyl base.

Examples of the saturated hydrocarbon group having a fluorine atom for R ^f6 include an alkyl group having a fluorine atom and an alicyclic hydrocarbon group having a fluorine atom.

Specific examples of the alkyl group having a fluorine atom include fluorinated alkyl groups such as difluoromethyl, trifluoromethyl, 1,1-difluoroethyl, 2,2-difluoroethyl, 2,2,2- trifluoroethyl, Perfluoroethyl, 1,1,2,2-tetrafluoropropyl, 1,1,2,2,3,3-hexafluoropropyl, perfluoroethylmethyl, 1-(trifluoromethyl) -1,2,2,2-tetrafluoroethyl, perfluoropropyl, 1-(trifluoromethyl)-2,2,2-trifluoroethyl, 1,1,2,2-tetrafluorobutane base, 1,1,2,2,3,3-hexafluorobutyl, 1,1,2,2,3,3,4,4-octafluorobutyl, perfluorobutyl, 1,1-bis (Trifluoro)methyl-2,2,2-trifluoroethyl, 2-(perfluoropropyl)ethyl, 1,1,2,2,3,3,4,4-octafluoropentyl, perfluoropentyl, 1,1,2,2,3,3,4,4,5,5-decafluoropentyl, 1,1-bis(trifluoromethyl)-2,2,3,3, 3-perfluoropropyl, 2-(perfluorobutyl)ethyl, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl, 1,1,2,2, 3,3,4,4,5,5,6,6-dodecafluorohexyl, perfluoropentylmethyl and perfluorohexyl.

Examples of the alicyclic hydrocarbon group having a fluorine atom include fluorinated cycloalkyl groups such as perfluorocyclohexyl and perfluoroadamantyl.

In the formula (a4-2), L ⁴⁴ is preferably a C2 to C4 alkanediyl group, and more preferably an ethylidene group.

R ^f6 is preferably a C1 to C6 fluorinated alkyl group.

Examples of the structural unit represented by the formula (a4-2) include the structural unit represented by the formula (a4-1-1) to the formula (a4-1-11) and wherein the methyl group corresponding to R ^f5 has been replaced by a hydrogen atom structural unit.

Specific examples of the structural unit (a4-1) include the structural unit represented by the formula (a4-3).

In the formula, R ^f7 represents a hydrogen atom or a methyl group.

L ⁵ represents a C1 to C6 alkanediyl group.

A ^f13 represents a C1 to C18 saturated hydrocarbon group which may have a fluorine atom.

X ^f12 represents carbonyloxy or oxycarbonyl.

A ^f14 represents a C1 to C17 saturated hydrocarbon group which may have a fluorine atom, provided that one or both of A ^f13 and A ^f14 represents a fluorine-containing aliphatic hydrocarbon group.

Examples of the alkanediyl group of L ⁵ include the same alkanediyl groups as the alkanediyl group of L ^4a .

A ^f13 further includes a combined group of a chain hydrocarbon group and an alicyclic hydrocarbon group.

Regarding A ^f13 , the chain hydrocarbon group or alicyclic hydrocarbon group which may have a fluorine atom is preferably a divalent saturated chain hydrocarbon group which may have a fluorine atom, and more preferably a perfluoroalkanediyl group.

Examples of the divalent chain saturated hydrocarbon group which may have a fluorine atom include alkanediyl groups such as methylene, ethylidene, propanediyl, butanediyl and pentanediyl; and perfluoroalkanediyl groups such as difluoro Methylene, perfluoroethylidene, perfluoropropanediyl, perfluorobutanediyl and perfluoropentanediyl.

The divalent cyclic saturated hydrocarbon group which may have a fluorine atom may be a divalent monocyclic group or a polycyclic group.

Examples of the divalent monocyclic hydrocarbon group which may have a fluorine atom include cyclohexanediyl and perfluorocyclohexanediyl.

Examples of the divalent polycyclic hydrocarbon group which may have a fluorine atom include adamantanediyl, norbornanediyl, and perfluoroadamantanediyl.

Among the groups represented by A ^f14 , the aliphatic hydrocarbon group includes a chain saturated hydrocarbon group, a cyclic saturated hydrocarbon group, and a combined group of these saturated hydrocarbon groups.

Regarding A ^f14 , the chain hydrocarbon group or alicyclic hydrocarbon group which may have a fluorine atom is preferably a saturated aliphatic hydrocarbon group which may have a fluorine atom, and more preferably a perfluoroalkyl group.

Examples of the chain hydrocarbon group which may have a fluorine atom include trifluoromethyl, fluoromethyl, methyl, perfluoroethyl, 1,1,1-trifluoroethyl, 1,1,2,2-tetrafluoroethyl , ethyl, perfluoropropyl, 1,1,1,2,2-pentafluoropropyl, propyl, perfluorobutyl, 1,1,2,2,3,3,4,4-octafluoro Butyl, butyl, perfluoropentyl, 1,1,1,2,2,3,3,4,4-nonafluoropentyl, pentyl, hexyl, perfluorohexyl, heptyl, perfluoroheptyl , octyl and perfluorooctyl.

The alicyclic hydrocarbon group which may have a fluorine atom may be a monocyclic group or a polycyclic group.

Examples of the monovalent monocyclic hydrocarbon group which may have a fluorine atom include cyclopropyl, cyclopentyl, cyclohexyl, and perfluorocyclohexyl.

Examples of the polycyclic hydrocarbon group which may have a fluorine atom include adamantyl, norbornyl, and perfluoroadamantyl.

Examples of the combined group of the above-mentioned chain hydrocarbon group and alicyclic hydrocarbon group include cyclopropylmethyl, cyclobutylmethyl, adamantylmethyl, norbornylmethyl, and perfluoroadamantylmethyl.

In the formula (a4-3), L ⁵ is preferably an ethylidene group.

The chain hydrocarbon group or alicyclic hydrocarbon group represented by A ^f13 preferably has 6 or less, and more preferably 2 to 3 carbon atoms.

The chain hydrocarbon group or alicyclic hydrocarbon group represented by A ^f14 preferably has 3 to 12, and more preferably 3 to 10 carbon atoms.

A ^f14 preferably has a C3 to C12 alicyclic hydrocarbon group, and more preferably is a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group or an adamantyl group.

Examples of the structural unit represented by the formula (a4-3) preferably include the structural unit represented by the formula (a4-1'-1) to the formula (a4-1'-11) and a methyl group corresponding to R ^f7 therein A structural unit that has been replaced by a hydrogen atom.

The structural unit represented by the formula (a4-4) is as follows.

In formula (a4-4), R ^f21 represents a hydrogen atom or a methyl group; A ^f21 represents -(CH ₂ ) _j1 -, -(CH ₂ ) _j2 -O-(CH ₂ ) _j3 - or -(CH ₂ ) _j4 -CO-O-( _CH2 ) _j5- , wherein j1, j2, j3, j4 or j5 each independently represents an integer of 1 to 6; and R ^f22 represents a C1 to C10 hydrocarbon group having a fluorine atom.

R ^f22 is preferably a C1 to C10 alkyl group having a fluorine atom or a C3 to C10 alicyclic hydrocarbon group having a fluorine atom, more preferably a C1 to C10 alkyl group having a fluorine atom, and still more preferably C1 having a fluorine atom to C6 alkyl.

In formula (a4-4), A ^f21 is preferably -(CH ₂ ) _j1 -, more preferably methylene or ethylidene, and still more preferably methylene.

Examples of the structural unit represented by the formula (a4-4) preferably include the following and structural units represented by the following formula in which the methyl group corresponding to R ^f21 has been replaced with a hydrogen atom.

When the resin (A) has the structural unit (a4), the content thereof is preferably 1 mol % to 20 mol %, more preferably 2 mol % to 15 mol %, based on 100 mol % of all the structural units of the resin. mol %, and still more preferably 3 mol % to 10 mol %.

Other examples of the structural unit (s) include structural units having an acid-stable hydrocarbon group. The structural unit (s) having an acid-stable hydrocarbon group may be referred to as "structural unit (a5)".

Herein, the term "acid-stable hydrocarbon group" means such a hydrocarbon group which is not removed from the structural unit having the group by the action of the acid generated from the above-mentioned acid generator.

The acid-stable hydrocarbyl group may be a linear hydrocarbyl group, a branched hydrocarbyl group, or a cyclic hydrocarbyl group.

The structural unit having a hydrocarbon that is not removed therefrom by the action of an acid may have a linear hydrocarbon, a branched hydrocarbon, or a cyclic hydrocarbon, and is preferably an alicyclic hydrocarbon group.

Examples of the structural unit having an acid-stable hydrocarbon group include the structural unit represented by the formula (a5-1):

wherein R ⁵¹ represents a hydrogen atom or a methyl group; R ⁵² represents a C3 to C18 monovalent cycloaliphatic hydrocarbon group which may have a C1 to C8 monovalent aliphatic hydrocarbon group as a substituent, with the limitation that the alicyclic hydrocarbon group does not have the and L ⁵⁵ represents a single bond or a C1 to C18 divalent saturated hydrocarbon group in ^which a methylene group may be replaced by an oxygen atom or a carbonyl group.

The alicyclic hydrocarbon group represented by R ⁵² may be a monocyclic alicyclic hydrocarbon group or a polycyclic alicyclic hydrocarbon group.

Examples of alicyclic hydrocarbon groups include monocyclic hydrocarbon groups such as C3 to C18 cycloalkyl groups (eg, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl); and polycyclic alicyclic hydrocarbon groups such as adamantyl or Norbornyl.

Examples of aliphatic hydrocarbon groups include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, and 2-ethyl hexyl.

Examples of the alicyclic hydrocarbon group having a substituent include 3-hydroxyadamantyl and 3-methyladamantyl.

R ⁵² is preferably a C3 to C18 unsubstituted alicyclic hydrocarbon group, and more preferably an adamantyl group, a norbornyl group or a cyclohexyl group.

Examples of the divalent saturated hydrocarbon group represented by L ⁵⁵ include a divalent aliphatic hydrocarbon group and a divalent alicyclic hydrocarbon group, and a divalent aliphatic hydrocarbon group is preferable.

Examples of divalent aliphatic hydrocarbon groups include alkanediyl groups such as methylene, ethylidene, propanediyl, butanediyl, and pentanediyl.

The divalent alicyclic hydrocarbon group may be a monocyclic alicyclic hydrocarbon group or a polycyclic alicyclic hydrocarbon group.

Examples of divalent monocyclic hydrocarbon groups include cycloalkanediyl groups such as cyclopentanediyl and cyclohexanediyl. Examples of the divalent polycyclic alicyclic hydrocarbon group include adamantanediyl and norbornanediyl.

Examples of the divalent hydrocarbon group in which the methylene group has been replaced by an oxygen atom or a carbonyl group include the divalent hydrocarbon groups represented by the formula (L1-1) to the formula (L1-4).

In these formulas, ^* represents a bonding position of an oxygen atom.

X ^x1 is a carbonyloxy group or an oxycarbonyl group; and L ^x1 is a C1 to C16 divalent aliphatic saturated hydrocarbon group, and L ^x2 is a single bond or a C1 to C15 divalent chain hydrocarbon group or an alicyclic hydrocarbon group, with the limitation that L The total number of carbon atoms in ^x1 and L ^x2 is 16 or less.

^Lx3 is a C1 to C17 divalent aliphatic saturated hydrocarbon group, and ^Lx4 is a single bond or a C1 to C16 divalent chain hydrocarbon group or an alicyclic hydrocarbon group, with the limitation that the total number of carbon atoms in ^Lx3 and ^Lx4 is 17 or less than 17.

^Lx5 is a C1 to C15 divalent aliphatic saturated hydrocarbon group, and ^Lx6 and ^Lx7 are a single bond or a C1 to C14 divalent chain hydrocarbon group or an alicyclic hydrocarbon group, with the limitation that among ^Lx5 , ^Lx6 and ^Lx7 The total number of carbon atoms is 15 or less.

^Lx8 and ^Lx9 are each independently a single bond or a C1 to C12 divalent chain hydrocarbon group or an alicyclic hydrocarbon group, and ^Wx1 is a C3 to C15 divalent cyclic saturated hydrocarbon group, with the limitation that ^Lx8 , ^Lx9 and W The total number of carbon atoms in ^x1 is 15 or less.

L ^x1 is preferably a C1 to C8 divalent aliphatic saturated hydrocarbon group, and more preferably a methylene group or an ethylidene group.

L ^x2 is preferably a single bond or a C1 to C8 divalent aliphatic saturated hydrocarbon group, and more preferably a single bond.

L ^x3 is preferably a C1 to C8 divalent aliphatic saturated hydrocarbon group, and more preferably a methylene group or an ethylidene group.

L ^x4 is preferably a single bond or a C1 to C8 divalent aliphatic saturated hydrocarbon group, and more preferably a single bond, a methylene group or an ethylidene group.

L ^x5 is preferably a C1 to C8 divalent aliphatic saturated hydrocarbon group, and more preferably a methylene group or an ethylidene group.

L ^x6 is preferably a single bond or a C1 to C8 divalent aliphatic saturated hydrocarbon group, and more preferably a methylene group or an ethylidene group.

L ^x7 is preferably a single bond or a C1 to C8 divalent aliphatic saturated hydrocarbon group, and more preferably a methylene group or an ethylidene group.

L ^x8 is preferably a single bond or a C1 to C8 divalent aliphatic saturated hydrocarbon group, and more preferably a single bond or a methylene group.

L ^x9 is preferably a single bond or a C1 to C8 divalent aliphatic saturated hydrocarbon group, and more preferably a single bond or a methylene group.

W ^x1 is preferably a C3 to C10 divalent cyclic saturated hydrocarbon group, and more preferably cyclohexanediyl or adamantanediyl.

Examples of the group represented by formula (L1-1) include the following.

In these formulas, ^* represents a bonding position of an oxygen atom.

Examples of the group represented by formula (L1-2) include the following.

In these formulas, ^* represents a bonding position of an oxygen atom.

Examples of the group represented by formula (L1-3) include the following.

In these formulas, ^* represents a bonding position of an oxygen atom.

Examples of the group represented by the formula (L1-4) include the following.

In these formulas, ^* represents a bonding position of an oxygen atom.

L ⁵⁵ is preferably a single bond or a group represented by formula (L1-1).

Examples of the structural unit represented by the formula (a5-1) include the following and structural units in which the methyl group in each formula has been replaced by a hydrogen atom.

When the resin (A) has the structural unit (a5), the content thereof is preferably 1 mol % to 30 mol %, more preferably 2 mol % to 20 mol % based on 100 mol % of the total structural units of the resin. mol %, and still more preferably 3 mol % to 15 mol %.

<Structural unit (II)>

The resin (A) may contain a structural unit that is decomposed by irradiation to generate an acid. The structural unit is referred to as "structural unit (II)". Examples of the structural unit (II) include the structural unit described in JP2016-79235A1.

The structural unit (II) preferably comprises a sulfonate group or a carboxylate group and an organic cation or S ⁺ group and an organic anion at its side chain.

The structural unit (II) comprising a sulfonate group or a carboxylate group and an organic cation at its side chain is preferably represented by the formula (II-2-A'):

wherein X ^III3 represents a C1 to C18 divalent in which a methylene group can be replaced by -O-, -S- or -CO- and in which a hydrogen atom can be replaced by a fluorine atom, a hydroxyl group or a C1 to C6 alkyl group which can have a fluorine atom A saturated hydrocarbon group, A ^x1 represents a C1 to C8 alkanediyl group or a C1 to C6 perfluoroalkyl group in which a hydrogen atom can be replaced by a fluorine atom, RA ^- represents a sulfonate group or a carboxylate group, R ^III3 represents a hydrogen atom, halogen atom or a C1 to C6 alkyl group in which a hydrogen atom may be replaced by a halogen atom, and ZA ⁺ represents an organic cation.

For R ^III3 , examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

For R ^III3 , examples of halogen-containing alkyl groups include perfluoromethyl and perfluoroethyl.

For A ^X1 , examples of alkanediyl include methylene, ethylidene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane- 1,6-diyl, ethane-1,1-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-2,2-diyl, pentane-2,4 -diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl and 2-methylbutane-1,4 - Two bases.

For X ^III3 , examples of divalent aliphatic hydrocarbon groups include linear alkanediyl groups, branched alkanediyl groups, monocyclic alicyclic hydrocarbons, polycyclic alicyclic hydrocarbons, and any combination of these groups, specific examples of which include Linear alkanediyl such as methylene, ethylidene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, pentane-1,5-diyl Diyl, Hexane-1,6-diyl, Heptane-1,7-diyl, Octane-1,8-diyl, Nonane-1,9-diyl, Decane-1,10- Diyl, undecane-1,11-diyl, dodecane-1,12-diyl; branched alkanediyl such as butane-1,3-diyl, 2-methylpropane-1, 3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl and 2-methylbutane-1,4-diyl; cycloalkanediyl such as cyclobutane Alkane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl and cyclooctane-1,5-diyl; and divalent polycyclic alicyclic Hydrocarbyl groups such as norbornane-1,4-diyl, norbornane-2,5-diyl, adamantane-1,5-diyl and adamantane-2,6-diyl.

Examples of the saturated hydrocarbon group in which the methylene group has been replaced by -O-, -S- or -CO- include divalent groups represented by formula (X1) to formula (X53).

^In each ^formula , ^X3 represents a C1 to C16 divalent hydrocarbon group, ^X4 represents a C1 to C15 divalent hydrocarbon group, X5 represents a C1 to C13 divalent hydrocarbon group, X6 represents a C1 to C14 divalent hydrocarbon group, and ^X7 represents a C1 to C14 divalent hydrocarbon group A C14 divalent hydrocarbon group, and X ⁸ represents a C1 to C13 divalent hydrocarbon group, and * represents the binding position of A ^x1 , with the restriction that each divalent group represented by one of the formula (X1) to the formula (X53) Has a total of 1 to 17 carbon atoms.

Examples of organic cations represented by ZA ⁺ include organic onium cations such as organic peronium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations.

Among them, organic pericium cations and organic iodonium cations are preferred, and pericium cations are more preferred, especially aryl pericynium cations.

The structural unit represented by the formula (II-2-A') is preferably represented by the formula (II-2-A):

wherein X ^III3 , R ^III3 and ZA ⁺ are as defined above; R ^III2 and R ^III4 each independently represent a hydrogen atom, a fluorine atom or a C1 to C6 perfluoroalkyl group; z represents an integer from 0 to 6; and Q ^a and Q ^b each independently represents a fluorine atom or a C1 to C6 perfluoroalkyl group.

For Q ^a , Q ^b , R ^III2 and R ^III4 , examples of perfluoroalkyl groups include trifluoromethyl, pentafluoroethyl, heptafluoropropyl, nonafluorobutyl, undecafluoropentyl, and tridecafluorohexyl , and preferably trifluoromethyl.

The structural unit represented by the formula (II-2-A) is preferably represented by the formula (II-2-A-1):

wherein R ^III2 , R ^III3 , R ^III4 , Q ^a , Q ^b , z and ZA ⁺ are as defined above; R ^III5 represents a C1 to C12 saturated hydrocarbon group; and X ^I2 represents wherein methylene can be replaced by -O-, -S- or -CO- substituted and a C1 to C18 divalent saturated hydrocarbon group in which a hydrogen atom may be replaced by a halogen atom or a hydroxyl group.

For R ^III5 , examples of saturated hydrocarbon groups include alkane groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, 2- Ethylhexyl and dodecyl.

For X ^I2 , examples of the divalent saturated hydrocarbon group include the same examples as the divalent saturated hydrocarbon group of X ^III3 .

The structural unit represented by the formula (II-2-A-1) is preferably represented by the formula (II-2-A-2):

wherein R ^III3 , R ^III5 and ZA ⁺ are as defined above; and n and m each independently represent 1 or 2.

Examples of the structural unit represented by the formula (II-2-A') include the following and the structural unit described in WO2012/050015A1.

The structural unit (II) comprising an S ⁺ group and an organic anion at its side chain is preferably represented by the formula (II-1-1):

wherein A ^II1 represents a single bond or a divalent linking group, R ^II1 represents a C6 to C18 divalent aromatic hydrocarbon group, R ^II2 and R ^II3 each independently represent a C1 to C18 hydrocarbon group or together with S ⁺ bonded thereto a ring Structure, R ^II4 represents a hydrogen atom, a halogen atom, or a C1 to C6 alkyl group in which a hydrogen atom may be replaced by a halogen atom, and A ^- represents an organic anion.

For R ^III1 , examples of the aromatic hydrocarbon group include phenylene and naphthylene.

For R ^II2 and R ^II3 , examples of hydrocarbyl groups include alkyl groups, alicyclic hydrocarbyl groups, aromatic hydrocarbyl groups, and any combination of these groups.

For R ^II4 , examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

For R ^II4 , examples of halogen-containing alkyl groups include perfluoromethyl and perfluoroethyl.

For A ^II1 , examples of divalent linking groups include C1 to C18 divalent saturated hydrocarbon groups in which methylene groups can be replaced by -O-, -S-, or -CO-. Specific examples of the divalent linking group include the same saturated hydrocarbon groups represented by X ^III3 .

Examples of the cation of the structural unit represented by the formula (II-1-1) include the following.

Examples ^of the organic anions represented by A- include sulfonate anions, sulfonamidoimide anions, sulfonamidomethide anions, and carboxyoxy anions.

Among them, the sulfonate anion is preferable. For A ⁻ , the sulfonate anion is preferably the same as the anion used for the salt represented by formula (B1).

For A ⁻ , examples of the sulfonylimide anion include the following.

For A ⁻ , examples of the sulfonyl methide anion include the following.

For A ⁻ , examples of the carbonyloxy anion include the following.

Examples of the structural unit represented by the formula (II-1-1) include the following.

When the resin (A) has the structural unit (II), the content thereof is preferably 1 mol % to 20 mol %, more preferably 2 mol % to 15 mol % based on 100 mol % of the total structural units of the resin. mol%, more preferably 3 mol% to 10 mol%.

The resin (A) is preferably a resin composed of the structural unit (a1) and the structural unit (s).

The structural unit (a1) is preferably one selected from the group consisting of the structural unit (a1-0), the structural unit (a1-1) and the structural unit (a1-2), especially having cyclohexyl or cyclopentyl base structural unit. More preferably, the resin (A) has a structure selected from the group consisting of the structural unit (a1-0), the structural unit (a1-1) and the structural unit (a1-2) two structural units in , especially those with cyclohexyl or cyclopentyl.

The structural unit (s) is preferably one selected from the group consisting of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably the structural unit (a2-A) or the structural unit (a2-1). The structural unit (a3) is preferably the structural unit (a3-1), the structural unit (a3-2) and the structural unit (a3-4).

Resin (A) can be produced according to known polymerization methods such as radical polymerization.

The resin typically has a weight average molecular weight of 2,000 or more, preferably a weight average molecular weight of 2,500 or more, and more preferably a weight average molecular weight of 3,000 or more. The resin typically has a weight average molecular weight of 50,000 or less, more preferably a weight average molecular weight of 30,000 or less, and more preferably a weight average molecular weight of 15,000 or less.

The weight average molecular weight can be measured using gel permeation chromatography.

The composition of the present disclosure may have another resin other than the resin (A).

Another resin other than the resin (A) does not include the structural unit (a1).

Another resin other than the resin (A) may include the structural unit (a2), the structural unit (a3), the structural unit (a4), and the structural unit (a5).

Examples of another resin other than the resin (A) include a resin containing the structural unit (a4) or a resin consisting of the structural unit (a4) and the structural unit (a5) [these resins are collectively referred to as "resin (X)" ].

In the resin (X), the content of the structural unit (a4) is preferably 30 mol % or more, more preferably 40 mol %, based on the total of the structural units in the resin. mol % or more than 40 mol %, and still more preferably 45 mol % or more.

The resin (X) usually has a weight average molecular weight of 6000 or more, and preferably has a weight average molecular weight of 7000 or more. The resin typically has a weight average molecular weight of 80,000 or less, and preferably has a weight average molecular weight of 60,000 or less.

The weight average molecular weight can be measured using known methods such as liquid chromatography or gas chromatography.

When the photoresist composition contains resin (X), based on 100 parts of resin (A), the content of the resin is preferably 1 to 60 parts by weight, more preferably 1 to 50 parts by weight, and then It is more preferably 1 part by weight to 40 parts by weight, still more preferably 1 part by weight to 30 parts by weight, and still more preferably 1 part by weight to 8 parts by weight.

The total content of the resin in the photoresist composition of the present invention is usually 80% by mass or more, more preferably 90% by mass or more, based on the sum of the solid components, and the total content of the solid components is 90% by mass or more. The meter is usually 99% by mass or less. In this specification, "solid components" means components other than the solvent in the photoresist composition.

The resin can be obtained by polymerizing the corresponding monomer or monomers. The polymerization reaction is usually carried out in the presence of free radical initiators. Such polymerization can be carried out according to known methods.

<Solvent>

Preferably, the photoresist composition of the present disclosure further contains a solvent.

Based on the total amount of the photoresist composition of the present invention, the amount of the solvent is usually 90 % by weight or greater than 90% by weight, preferably 92% by weight or greater, and preferably 94% by weight or greater. The amount of the solvent is usually 99.9 wt % or less and preferably 99 wt % or less, based on the total amount of the photoresist composition of the present invention. The content can be measured using known methods such as liquid chromatography or gas chromatography.

Examples of solvents include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate, and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; esters such as acetic acid ethyl esters, butyl acetate, amyl acetate and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; and cyclic esters such as gamma-butyrolactone.

<quencher>

The photoresist composition of the present disclosure may further contain a quencher, such as a basic compound. A "quencher" has the property that it can capture acids, especially acids generated from acid generators due to exposure to light used for lithography.

Examples of quenchers include basic compounds (eg, basic nitrogen-containing organic compounds) and salts that produce acids that are less acidic than those produced from acid generators.

Examples of basic nitrogen-containing organic compounds include amine compounds such as aliphatic amines, aromatic amines, and ammonium salts. Examples of aliphatic amines include primary amines, secondary amines, and tertiary amines. Examples of aromatic amines include aromatic amines.

Examples of quenchers include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-methylaniline, 3-methylaniline or 4-methylaniline, 4-nitroaniline, N- methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, Decylamine, Dibutylamine, Amylamine, Dioctylamine, Triethylamine, Trimethylamine, Tripropylamine, Tributylamine, Tripentylamine, Trihexylamine, Triheptylamine, Trioctylamine, Trinonylamine, Tridecylamine Amine, Methyldibutylamine, Methyldipentylamine, Methyldihexylamine, Methyldicyclohexylamine, Methyldiheptylamine, Methyldioctylamine, Methyldinonylamine, Methyldidecylamine , ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tricyclohexylamine [2-(2-Methoxyethoxy)ethyl]amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamine -1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyl Diphenylmethane, piperazine, morpholine, piperidine, hindered amine compounds with piperidine structure, 2,2'-methylene dianiline, imidazole, 4-methylimidazole, pyridine, 4- Methylpyridine, 1,2-bis(2-pyridyl)ethane, 1,2-bis(4-pyridyl)ethane, 1,2-bis(2-pyridyl)ethane, 1,2- Bis(4-pyridyl)ethylene, 1,3-bis(4-pyridyl)propane, 1,2-bis(4-pyridyloxy)ethane, bis(2-pyridyl)one, 4,4 '-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-lutidine amine and bipyridine.

Examples of quaternary ammonium hydroxide include tetramethylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, (3-trifluoromethylammonium hydroxide) phenyl)trimethylammonium hydroxide and (2-hydroxyethyl)trimethylammonium hydroxide (so-called "choline").

Regarding a salt that produces an acid that is less acidic than that produced from an acid generator, the acidity of the salt is shown by the acid dissociation constant (pKa).

Acid dissociation constants for acids derived from salts used as quenchers are typically -3 < pKa.

The salt used for the quencher is preferably a salt with an acid dissociation constant of -1<pKa<7, and more preferably a salt with an acid dissociation constant of 0<pKa<5.

Specific examples of salts used for quenchers include the following: onium carboxylates (eg, salts of formula (D)) and those described in US2012/328986A1, US2011/171576A1, US2011/201823A1, JP2011-39502A1, and US2011/200935A1 mentioned salt.

The photoresist composition preferably includes an onium carboxylate, and more preferably a salt of formula (D).

In formula (D), R ^D1 and R ^D2 respectively represent C1 to C12 monovalent hydrocarbon group, C1 to C6 alkoxy group, C2 to C7 alkoxy group, C2 to C7 alkoxy group, C2 to C7 alkoxycarbonyl group, nitro group or halogen atom. The symbols m' and n' each independently represent an integer of 0 to 4, preferably an integer of 0 to 2, and more preferably 0.

Examples of the compound represented by formula (D) include the following.

The content of the quencher is preferably 0.01% by mass to 5% by mass, more preferably 0.01% by mass to 4% by mass, still more preferably 0.01% by mass to 3% by mass, and still more preferably, based on the total of the solid components. Preferably it is 0.01 mass % to 1 mass %.

If necessary, the photoresist composition of the present invention may contain a small amount of various additives such as sensitizers, dissolution inhibitors, other polymers, surfactants, stabilizers, and dyes, as long as the effects of the present invention are not hindered.

The photoresist composition of the present invention can be prepared in the following manner: usually in a solution The acid generator containing the salt (aa) and the resin (A) and (if necessary) a quencher and/or an additive are mixed in a suitable composition ratio, if necessary, and then using a pore size of 0.003 microns to 0.2 This mixture is filtered through a micron filter.

The order of mixing of the components is not limited to any particular order. The temperature at the time of mixing the components is usually 10°C to 40°C, and the temperature may be selected according to the resin or the like. The mixing time is usually 0.5 hours to 24 hours, and the mixing time can be selected according to the temperature. The manner of mixing these components is not limited to a particular manner. The components can be mixed by stirring.

The amounts of the components in the photoresist composition can be adjusted by selecting the amounts to be used in the production of the photoresist composition.

The photoresist composition of the present disclosure is suitable for chemically amplified photoresist composition.

A photoresist pattern can be produced by the following steps (1) to (5): (1) a step of applying the photoresist composition of the present invention on a substrate, (2) a step of forming a film of the composition by performing drying, (3) a step of exposing the composition film to radiation, (4) a step of baking the exposed composition film, and (5) a step of developing the baked composition film.

Applying the photoresist composition to the substrate is typically performed using conventional equipment (eg, spin coaters). Examples of substrates include silicon or quartz wafers on which sensors, circuits, transistors, or the like are formed.

Formation of the composition film is usually performed using a heating device such as a hot plate or a pressure reducer, and the heating temperature is usually 50°C to 200°C. When the pressure is reduced during heating, the operating pressure is typically ¹ Pa to 1.0*105 Pascal (Pa). The heating time is usually 10 seconds to 180 seconds.

The obtained composition film is exposed to radiation using an exposure system. Exposure is typically performed with a mask having a pattern corresponding to the desired photoresist pattern. Examples of exposure sources include light sources that radiate laser light in the ultraviolet region, such as KrF excimer laser (wavelength: 248 nm), ArF excimer laser (wavelength: 193 nm), and F ₂ laser ( Wavelength: 157 nm); irradiated in the far ultraviolet region or vacuum ultraviolet by wavelength conversion of the laser light from a solid-state laser light source (such as yttrium aluminum garnet (YAG) or semiconductor laser) A light source for harmonic laser light in the region; and a light source for irradiating an electron beam or extreme ultraviolet (EUV) light.

The temperature at which the exposed composition film is baked is usually 50°C to 200°C and preferably 70°C to 150°C.

The development of the baked composition film is usually carried out using a developing apparatus. Development methods include dipping method, paddle method, spray method and dynamic dispensing method. The development temperature is preferably 5°C to 60°C, and the development time is preferably 5 seconds to 300 seconds.

The positive-type photoresist pattern and the negative-type photoresist pattern can be obtained by developing according to the developer to be used for development.

When a positive photoresist pattern is prepared from the photoresist composition of the present invention, development can be performed using an alkaline developer. The alkaline developer to be used can be any of various alkaline aqueous solutions used in the art. In general, tetramethyl An aqueous solution of ammonium hydroxide or (2-hydroxyethyl)trimethylammonium hydroxide (commonly referred to as "choline"). Alkaline developers may contain surfactants.

After development, the photoresist film with the photoresist pattern is preferably washed with ultrapure water and preferably the photoresist film and water remaining on the substrate are removed therefrom.

When a negative photoresist pattern is prepared from the photoresist composition of the present invention, development can be performed with a developer containing an organic solvent, and such a developer is sometimes referred to as an "organic developer".

Examples of organic solvents for organic developers include ketone solvents such as 2-hexanone, 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols Ether solvents such as propylene glycol monomethyl ether; amide solvents such as N,N-dimethylacetamide; and aromatic hydrocarbon solvents such as anisole.

In the organic developer, the content of the organic solvent is preferably 90% by weight to 100% by weight, and more preferably 95% by weight to 100% by weight. Preferably, the organic developer consists essentially of an organic solvent.

Among them, the organic developer is preferably a developer containing butyl acetate and/or 2-heptanone.

The total content of butyl acetate and 2-heptanone is preferably 90 to 100% by weight, more preferably 95 to 100% by weight. Preferably, the organic developer consists essentially of butyl acetate and/or 2-heptanone.

Organic developers may contain surfactants or very small amounts of water.

Development with the organic developer can be stopped by replacing the developer with a solvent other than the organic developer, such as an alcohol.

The photoresist composition of the present invention is suitable for KrF excimer laser lithography, ArF excimer laser lithography, extreme ultraviolet (EUV) lithography, EUV immersion lithography and electron beam, EB) lithography.

example

The disclosed invention will be more specifically explained by means of examples, which should not be construed as limiting the scope of the invention.

Unless expressly stated otherwise, "%" and "parts" used to indicate the content of any components and the amount of any materials used in the following examples and comparative examples are by weight.

The weight average molecular weight of any material used in the following examples is the value obtained by gel permeation chromatography under the following conditions.

Columns: HLC-8120GPC type (three columns with guard columns), TSKgel Multipore HXL-M, manufactured by TOSOH CORPORATION

Solvent: tetrahydrofuran, flow rate: 1.0 ml/min

Detector: refractive index (RI) detector

Column temperature: 40℃

Injection volume: 100 microliters (μL)

Standard Reference Material: Standard Polystyrene

The structure of the compound was determined by: Mass spectrometry (Liquid Chromatography: Model 1100, by AGILENT TECHNOLOGIES LTD.), mass spectrometry: liquid chromatography (liquid chromatography, LC)/mass selective detector (mass selective detector, MSD) type, manufactured by Agilent Technologies Co., Ltd.).

Example 1

In a reactor, 7 parts of the salt represented by the formula (I-1-a), 6.5 parts of the compound represented by the formula (I-1-b), 35 parts of chloroform, 14 parts of acetonitrile and 14 parts of dimethylmethane were mixed The amide was mixed and stirred at 23°C for 30 minutes.

Next, 0.07 part of p-toluenesulfonic acid was added and then refluxed for 3 hours while stirring. The obtained mixture was cooled to 23°C, and then 155 parts of chloroform was added thereto, followed by filtration. To the obtained filtrate, 40 parts of a 5% aqueous sodium carbonate hydrate solution was added and stirred at 23°C for 30 minutes. The obtained mixture was then left to stand to separate the organic layer therefrom.

To the obtained organic layer was added 45 parts of ion-exchanged water and then stirred at 23° C. for 30 minutes, and then the organic layer was separated therefrom. The organic layer was washed three times with water in the above-described manner.

To the obtained organic layer was added 95 parts of ethyl acetate, and the obtained mixture was stirred. The supernatant was then removed therefrom. The obtained residue was dissolved in acetonitrile, and then the obtained solution was concentrated to obtain 4.38 parts of the salt represented by the formula (I-1-c).

In the reactor, 4.34 parts of the salt represented by the formula (I-1-c), 50 parts of chloroform and 1.28 parts of pyridine were mixed and stirred at 23°C for 30 minutes.

Next, 3.79 parts of the compound represented by the formula (I-1-d) was added and then stirred at 23°C for 12 hours.

To the obtained mixture was added 20 parts of ion-exchanged water and then stirred at 23° C. for 30 minutes. The obtained mixture was then left to stand to separate the organic layer therefrom.

To the obtained organic layer, 15 parts of a 5% aqueous oxalic acid solution was added and then stirred at 23° C. for 30 minutes, and then the organic layer was separated therefrom.

To the obtained mixture was added 20 parts of ion-exchanged water and then stirred at 23° C. for 30 minutes, and then the organic layer was separated therefrom. The organic layer was washed three times with water in the above-described manner.

To the obtained organic layer, 1 part of acetonitrile and 30 parts of t-butyl methyl ether were added, and the obtained mixture was stirred. The supernatant was then removed therefrom. The obtained residue was dissolved in acetonitrile, and then the obtained solution was concentrated to obtain 4.22 parts of the salt represented by the formula (I-1).

Mass (electrospray ion (ESI) (+), spectrum): M ⁺ 263.1

Mass (ESI(-), Spectrum): M ^- 467.1

Example 2

In a reactor, 7.18 parts of the salt represented by the formula (I-10-a), 6.5 parts of the compound represented by the formula (I-1-b), 35 parts of chloroform, 14 parts of acetonitrile and 14 parts of dimethylmethane were mixed The amide was mixed and stirred at 23°C for 30 minutes.

Next, 0.07 part of p-toluenesulfonic acid was added and then refluxed for 3 hours while stirring. The obtained mixture was cooled to 23°C, and then 155 parts of chloroform was added thereto, followed by filtration. To the obtained filtrate, 40 parts of a 5% aqueous sodium carbonate hydrate solution was added and stirred at 23°C for 30 minutes. The obtained mixture was then left to stand to separate the organic layer therefrom.

To the obtained organic layer was added 45 parts of ion-exchanged water and then stirred at 23° C. for 30 minutes, and then the organic layer was separated therefrom. The organic layer was washed three times with water in the above-described manner.

To the obtained organic layer was added 95 parts of ethyl acetate, and the obtained mixture was stirred. The supernatant was then removed therefrom. the residues obtained The residue was dissolved in acetonitrile, and then the obtained solution was concentrated to obtain 4.62 parts of the salt represented by the formula (I-10-c).

In the reactor, 4.43 parts of the salt represented by the formula (I-10-c), 50 parts of chloroform and 1.28 parts of pyridine were mixed and stirred at 23°C for 30 minutes.

Next, 3.79 parts of the compound represented by the formula (I-1-d) was added and then stirred at 23°C for 12 hours.

To the obtained mixture was added 20 parts of ion-exchanged water and then stirred at 23° C. for 30 minutes. The obtained mixture was then left to stand to separate the organic layer therefrom.

To the obtained organic layer, 15 parts of a 5% aqueous oxalic acid solution was added and then stirred at 23° C. for 30 minutes, and then the organic layer was separated therefrom.

To the obtained mixture was added 20 parts of ion-exchanged water and then stirred at 23° C. for 30 minutes, and then the organic layer was separated therefrom. The organic layer was washed three times with water in the above-described manner.

To the obtained organic layer, 1 part of acetonitrile and 30 parts of t-butyl methyl ether were added, and the obtained mixture was stirred. The supernatant was then removed therefrom. The obtained residue was dissolved in acetonitrile, and then the obtained solution was concentrated to obtain 3.89 parts of the salt represented by the formula (I-10).

Mass (ESI(+), Spectrum): M ⁺ 263.1

Mass (ESI(-), Spectrum): M ^- 481.1

Example 3

In a reactor, 6.69 parts of the salt represented by the formula (I-49-a), 6.5 parts of the compound represented by the formula (I-1-b), 35 parts of chloroform, 14 parts of acetonitrile and 14 parts of dimethylmethane were mixed The amide was mixed and stirred at 23°C for 30 minutes.

Next, 0.07 part of p-toluenesulfonic acid was added and then refluxed for 3 hours while stirring. The obtained mixture was cooled to 23°C, and then 155 parts of chloroform was added thereto, followed by filtration. To the obtained filtrate, 40 parts of a 5% aqueous sodium carbonate hydrate solution was added and stirred at 23°C for 30 minutes. The obtained mixture was then left to stand to separate the organic layer therefrom.

To the obtained organic layer was added 45 parts of ion-exchanged water and then stirred at 23° C. for 30 minutes, and then the organic layer was separated therefrom. The organic layer was washed three times with water in the above-described manner.

To the obtained organic layer was added 95 parts of ethyl acetate, and the obtained mixture was stirred. The supernatant was then removed therefrom. the residues obtained The residue was dissolved in acetonitrile, and then the obtained solution was concentrated to obtain 4.44 parts of the salt represented by the formula (I-49-c).

In the reactor, 4.18 parts of the salt represented by the formula (I-49-c), 50 parts of chloroform and 1.28 parts of pyridine were mixed and stirred at 23° C. for 30 minutes. Next, 3.79 parts of the compound represented by the formula (I-1-d) was added and then stirred at 23°C for 12 hours. To the obtained mixture was added 20 parts of ion-exchanged water and then stirred at 23° C. for 30 minutes. The obtained mixture was then left to stand to separate the organic layer therefrom. To the obtained organic layer, 15 parts of a 5% aqueous oxalic acid solution was added and then stirred at 23° C. for 30 minutes, and then the organic layer was separated therefrom.

To the obtained mixture was added 20 parts of ion-exchanged water and then stirred at 23° C. for 30 minutes, and then the organic layer was separated therefrom. The organic layer was washed three times with water in the above-described manner.

To the obtained organic layer, 1 part of acetonitrile and 30 parts of t-butyl methyl ether were added, and the obtained mixture was stirred. The supernatant was then removed therefrom. The obtained residue was concentrated to obtain 4.08 parts of the salt represented by the formula (I-49).

Mass (ESI(+), Spectrum): M ⁺ 237.1

Mass (ESI(-), Spectrum): M ^- 467.1

Example 4

In a reactor, 6.87 parts of the salt represented by the formula (I-58-a), 6.5 parts of the compound represented by the formula (I-1-b), 35 parts of chloroform, 14 parts of acetonitrile and 14 parts of dimethylmethane were mixed The amide was mixed and stirred at 23°C for 30 minutes.

Next, 0.07 part of p-toluenesulfonic acid was added and then refluxed for 3 hours while stirring. The obtained mixture was cooled to 23°C, and then 155 parts of chloroform was added thereto, followed by filtration. To the obtained filtrate, 40 parts of a 5% aqueous sodium carbonate hydrate solution was added and stirred at 23°C for 30 minutes. The obtained mixture was then left to stand to separate the organic layer therefrom.

To the obtained organic layer was added 45 parts of ion-exchanged water and then stirred at 23° C. for 30 minutes, and then the organic layer was separated therefrom. The organic layer was washed three times with water in the above-described manner.

To the obtained organic layer was added 95 parts of ethyl acetate, and the obtained mixture was stirred. The supernatant was then removed therefrom. the residues obtained The residue was dissolved in acetonitrile, and then the obtained solution was concentrated to obtain 4.55 parts of the salt represented by the formula (I-58-c).

In the reactor, 4.27 parts of the salt represented by the formula (I-58-c), 50 parts of chloroform and 1.28 parts of pyridine were mixed and stirred at 23°C for 30 minutes. Next, 3.79 parts of the compound represented by the formula (I-1-d) was added and then stirred at 23°C for 12 hours. To the obtained mixture was added 20 parts of ion-exchanged water and then stirred at 23° C. for 30 minutes. The obtained mixture was then left to stand to separate the organic layer therefrom. To the obtained organic layer, 15 parts of a 5% aqueous oxalic acid solution was added and then stirred at 23° C. for 30 minutes, and then the organic layer was separated therefrom.

To the obtained mixture was added 20 parts of ion-exchanged water and then stirred at 23° C. for 30 minutes, and then the organic layer was separated therefrom. The organic layer was washed three times with water in the above-described manner.

To the obtained organic layer, 1 part of acetonitrile and 30 parts of t-butyl methyl ether were added, and the obtained mixture was stirred. The supernatant was then removed therefrom. The obtained residue was concentrated to obtain 3.39 parts of the compound represented by the formula (I-58). Salt.

Mass (ESI(+), Spectrum): M ⁺ 237.1

Mass (ESI(-), Spectrum): M ^- 481.1

Example 5

In a reactor, 6.07 parts of the salt represented by the formula (I-53-a), 6.5 parts of the compound represented by the formula (I-1-b), 35 parts of chloroform, 14 parts of acetonitrile and 14 parts of dimethylmethane were mixed The amide was mixed and stirred at 23°C for 30 minutes.

Next, 0.07 part of p-toluenesulfonic acid was added and then refluxed for 3 hours while stirring. The obtained mixture was cooled to 23°C, and then 155 parts of chloroform was added thereto, followed by filtration. To the obtained filtrate, 40 parts of a 5% aqueous sodium carbonate hydrate solution was added and stirred at 23°C for 30 minutes. The obtained mixture was then left to stand to separate the organic layer therefrom.

To the obtained organic layer was added 45 parts of ion-exchanged water and then stirred at 23° C. for 30 minutes, and then the organic layer was separated therefrom. The organic layer was washed three times with water in the above-described manner.

To the obtained organic layer was added 95 parts of ethyl acetate, and the obtained mixture was stirred. The supernatant was then removed therefrom. The obtained residue was dissolved in acetonitrile, and then the obtained solution was concentrated to obtain 4.62 parts of the salt represented by the formula (I-53-c).

In the reactor, 3.86 parts of the salt represented by the formula (I-53-c), 50 parts of chloroform and 1.28 parts of pyridine were mixed and stirred at 23°C for 30 minutes. Next, 3.79 parts of the compound represented by the formula (I-1-d) was added and then stirred at 23°C for 12 hours. To the obtained mixture was added 20 parts of ion-exchanged water and then stirred at 23° C. for 30 minutes. The obtained mixture was then left to stand to separate the organic layer therefrom. To the obtained organic layer, 15 parts of a 5% aqueous oxalic acid solution was added and then stirred at 23° C. for 30 minutes, and then the organic layer was separated therefrom.

To the obtained mixture was added 20 parts of ion-exchanged water and then stirred at 23° C. for 30 minutes, and then the organic layer was separated therefrom. The organic layer was washed three times with water in the above-described manner.

To the obtained organic layer, 1 part of acetonitrile and 30 parts of t-butyl methyl ether were added, and the obtained mixture was stirred. The supernatant was then removed therefrom. The obtained residue was concentrated to obtain 4.08 parts of the compound represented by the formula (I-53). Salt.

Mass (ESI(+), Spectrum): M ⁺ 237.1

Mass (ESI(-), Spectrum): M ^- 415.1

resin synthesis

The monomers used in the following synthesis examples are shown below.

These monomers are sometimes referred to as "monomer (X)", where (X) represents the symbol of the formula corresponding to the monomer. For example, the monomer represented by the formula (a1-1-3) is referred to as "monomer (a1-1-3)".

Synthesis Example 1

To 45/14/2.5/38.5 (monomer(a1-1-3)/monomer(a1-2-6)/monomer(a2-1-1)/monomer(a3-4-2)) The molar ratio of the mixed monomer (a1-1-3), monomer (a1-2-6), monomer (a2-1-1) and monomer (a3-4-2), added as Propyleneglycolmonomethylether acetate in an amount (by mass) 1.5 times the total parts of all monomers to prepare a mixture. To this mixture were added azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) in molar ratios of 1 mol% and 3 mol%, respectively, based on the molar amount of all monomers ) (azobis(2,4-dimethylvaleronitrile)) as an initiator, and the obtained mixture was heated at 73° C. for about 5 hours.

The obtained reaction mixture was poured into a large amount of a mixture of methanol and water to precipitate the resin, and then filtered.

The obtained filtrate was then dissolved in propylene glycol monomethyl ether acetate, and the filtrate solution was then poured into a mixture of methanol and water to reprecipitate the resin. This reprecipitation step was performed twice. As a result, a polymer having a weight average molecular weight of about 7800 was obtained in a yield of 69%. The polymer has the following structural units. The polymer is referred to as resin A1.

Resin Synthesis Example 2

The monomer (a5-1-1) was mixed with the monomer (a4-0-12) in a ratio of 50:50, and methyl isopropyl methyl iso-methyl was added in an amount of 1.2 times the total parts of all the monomers. butanone to prepare a solution. To this solution was added azobis(2,4-dimethylvaleronitrile) as a starting agent in a ratio of 3 mol % based on the molar amount of all monomers, And the obtained mixture was heated at 70°C for about 5 hours.

The obtained reaction mixture was poured into a large amount of a mixture of methanol and water to precipitate the resin, and then filtered.

As a result, a polymer having a weight average molecular weight of about 10,000 was obtained in a yield of 91%. The polymer has the following structural units. call the polymer a tree Fat X1.

Examples 6 to 17 and Comparative Examples 1 to 3

<Production of photoresist composition>

The following components listed in the table below were mixed and dissolved in the solvent described below, and then filtered through a fluororesin filter having a pore diameter of 0.2 μm to prepare a photoresist composition.

In Table 4, each of the characters represents the following components:

<resin>

A1: Resin A1, X1: Resin X1

<Salt (I)>

I-1: Salt represented by formula (I-1)

I-10: Salt represented by formula (I-10)

I-49: Salt represented by formula (I-49)

I-53: Salt represented by formula (I-53)

I-58: Salt represented by formula (I-58)

B1-21: A salt represented by formula (B1-21), produced by the method described in the example of JP2012-224611A1

B1-22: A salt represented by formula (B1-22), produced by the method described in the example of JP2012-224611A1

IX-1: A salt represented by the following formula, as in the example of JP2011-37837A1 prepared by the method

IX-2: A salt represented by the following formula, prepared by the method described in the example of JP2013-256496A1

IX-3: A salt represented by the following formula, prepared by the method described in the examples of US2017/0247323A1

<quencher>

D1: A compound of the following formula, which is manufactured by Tokyo Chemical Industries, Co., Ltd.

<Solvent>

A mixture of the following solvents

265 parts of propylene glycol monomethyl ether acetate

<Production of photoresist pattern>

The composition for an organic antireflection film (“ARC-29” manufactured by Nissan Chemical Co. Ltd.) was applied to a 12-inch silicon wafer and baked at 205°C for 60 seconds to form a 78 nm thick organic anti-reflection coating.

One of the photoresist compositions was then applied on the organic anti-reflection film by spin coating, so that the thickness of the film after drying (pre-baking) became 85 nm.

The resulting wafers were then prebaked on a direct hot plate for 60 seconds at the temperatures given in the row "PB" in Table 4.

On the wafer on which the photoresist film has been thus formed, an ArF excimer laser stepper for liquid immersion lithography ("XT: 1900Gi" from ASML Co., Ltd.: NA=1.35, 3/4 ring X-Y-pol. illumination) exposed the film through a mask, thereby forming a pattern of contact holes (hole pitch 90 nm/hole diameter 55 nm) while varying the exposure in a step-like manner. Ultrapure water was used as the medium for liquid immersion.

After the exposure, a post-exposure baking was performed for 60 seconds at the temperatures given in the "PEB" row in Table 4.

Next, using butyl acetate (a product of Tokyo Chemical Industry Co., Ltd.) Development was carried out in a dynamic dispensing method at 23°C for 20 seconds to obtain a negative photoresist pattern.

<Evaluation of Critical Dimension Uniformity (CDU)>

A photoresist pattern is formed by the same method as described above in which exposure is performed at an effective sensitivity. In this evaluation process, the effective sensitivity was determined as the exposure amount used to obtain a photoresist pattern having a hole diameter of 45 nm by exposure using the above-described mask.

Hole diameters were measured at 24 points for each hole of the pattern. The average value of the values determined as the pore diameter was defined as the average pore diameter of the one pore.

Regarding the mean hole diameter, a standard deviation was obtained based on a population consisting of 400 holes within the same wafer. The standard deviation was determined as the critical dimension uniformity value.

The results are shown in Table 5. Numerical values represent standard deviation values (nm).

The salt of the present disclosure is suitable for use as a component of a photoresist composition, and the photoresist composition containing the salt of the present disclosure can provide a photoresist pattern with excellent CD uniformity.

Claims (9)

A salt comprising an anion represented by formula (aa2):

wherein X ^a and X ^b each independently represent an oxygen atom or a sulfur atom, the ring W represents a C3 to C18 heterocycle having a carbonate structure and can have a substituent, and the ring W1 represents a can have a substituent and wherein the methylene group can be - O-, -S-, -CO- or -SO ₂ - substituted C3 to C18 non-aromatic hydrocarbon ring, L ¹ represents wherein a hydrogen atom can be replaced by a fluorine atom or a hydroxyl group and wherein a methylene group can be replaced by -O- or -CO-substituted C1 to C24 divalent saturated hydrocarbon group, and Q ¹ and Q ² each independently represent a fluorine atom or a C1 to C6 perfluoroalkyl group. The salt described in claim 1, comprising a cation and the anion represented by the formula (aa2). The salt according to claim 1 or claim 2, wherein the ring W1 represents an adamantane ring or a cyclohexane ring. The salt according to item 1 or item 2 of the claimed scope, wherein L ¹ is represented by formula (b1-1) or formula (b1-2):

wherein L ^b2 represents a single bond or a C1 to C22 divalent saturated hydrocarbon group wherein a hydrogen atom can be replaced by a fluorine atom; L ^b3 represents a single bond or wherein a hydrogen atom can be replaced by a hydroxyl or fluorine atom and wherein a methylene group can be replaced by an oxygen atom or A carbonyl-substituted C1 to C22 divalent saturated hydrocarbon group with the limitation that the total number of carbon atoms in L ^b2 and L ^b3 is at most 22; L ^b4 represents a C1 to C22 divalent saturated hydrocarbon group in which a hydrogen atom can be replaced by a fluorine atom; and L ^b5 represents a single bond or a C1 to C22 divalent saturated hydrocarbon group in which a hydrogen atom can be replaced by a hydroxyl group or a fluorine atom and in which a methylene group can be replaced by an oxygen atom or a carbonyl group, with the limitation that all carbon atoms of L ^b4 and L ^b5 Up to 22. The salt according to claim 1 or claim 2, wherein the ring W represents a 1,3-dioxan-2-one ring. An acid generator comprising the salt as described in item 1 or item 2 of the claimed scope. A photoresist composition comprising the acid generator as described in item 6 of the patent application scope and a resin, the resin comprising a structural unit having an acid-labile group. The photoresist composition of claim 7, further comprising a salt that generates an acid whose acidity is weaker than that generated from the acid generator. A process for producing a photoresist pattern, comprising the following steps (1) to (5): (1) applying the photoresist composition as described in item 7 or item 8 of the claimed scope on a substrate, (2) a step of forming a composition film by performing drying, (3) a step of exposing the composition film to radiation, (4) a step of baking the exposed composition film, and (5) A step of developing the baked composition film to thereby form a photoresist pattern.